The Book
To be honest, I haven't done much more than to flip through Death from the Skies. Rather than work my way through it as I usually would, I immediately opened it to the Stormraven and Stormtalon entries (I'm expecting a Stormraven and two Stormtalons to arrive from TheWarStore any day now). Once I committed those portions to memory, I took a few minutes to actually look at the rest of what my $33 bought me.
The book is beautiful, having been published in the colorful and detailed style that we've come to expect with 6th Edition 40K. After a few pages of artwork (including an awesome painting of a Heldrake crouched on a Valkyrie and burning a hole through its cockpit) you come to a short introduction. Following the introduction are about 15 pages describing the Battle for Cardrim, which is reprinted from the June 2012 White Dwarf ("Aerial Assault!"). Nearly 20 pages of air war missions and optional dogfighting rules follow. Some of these look interesting, but I don't really see our cabal playing too many of them. As usual, there are several pages of professionally painted models, several of which originally appeared in White Dwarf. The final 17 pages contain the updated rules for all flyers released prior to 6th Edition as well as a convenient reference page.
While the preceding content is interesting, I think most players are interested in the rules section. The book contains significant changes to the Stormtalon and introduces the Codex Space Marine version of the Stormraven; material that goes beyond the scope of the average FAQ. However, there appear to be very few, if any, significant changes to other flyers that haven't already been addressed elsewhere. A comparison between the Imperial Guard codex entries for the Valkyrie and the Vendetta and the entries in Death from the Skies shows that the only difference is the unit type and the deletion of the Deep Strike and Scout special rules (these changes have been addressed in the FAQs). While the FAQ for the Ork codex says that updated rules for their flyers are located in the new book, I couldn't find any substantial differences between the June 2012 White Dwarf and the compendium with the exception of unit type, which was already addressed in the 6th Edition rulebook. Points values and special rules seem to be the same except for the deletion of the obsolete Aerial Assault rule (more on that later). The terms "flyer" or "flying monstrous creature" have been added to the wording of rules that only mentioned skimmers before. And the Fighta Ace upgrade that gives the Dakkajet BS3 against flyers, jetbikes, skimmers, or zooming flying monstrous creatures has inexplicably been renamed as Flyboss. Unfortunately, I can't tell if there have been any other changes since I don't have the relevant codexes.
In short, the only ones who actually need the content of this book are Codex Space Marine players and Ork players who missed out on "Aerial Assault!". As an Ultramarines player who has wanted to field a Stormtalon since it was released and who has coveted the Stormraven since the earliest rumors indicated that flyer rules would be incorporated into 6th Edition, I fell into the category of those who needed Death from the Skies. I know that having to buy a $33 book just to get a few pages of updated flyer rules has become a sore point with hobbyists who have to be more frugal, but as a person with a bit more disposable income than some, I was happy to add such an attractive book to my collection. And from a more practical standpoint, this relatively low cost book allows me to see what any Necron/Ork/Dark Eldar/Marine player standing on the other side of the table might be bringing to the game. The various armies' flyers have a huge variety of unique weapons and abilities that can come as a nasty surprise to the unaware (I was certainly unsettled when Kevin demonstrated the Voidraven's S9 AP2 void lances and mines).
As I said before, the bulk of the changes affect Codex Space Marines. I'd read enough rumors about the revised rules that I wasn't really surprised by what I found, but it was still nice to see it for myself on the printed page. Here are some of the changes that will interest my fellow Astartes players:
The Stormraven
Well before I had the book in my hands, it had been officially confirmed that Codex Space Marines can now field the Stormraven. The in-universe reason given for why my Ultramarines can now take a Stormraven is very similar to the justification given for allowing other Chapters access to the Black Templar's Land Raider Crusader pattern:
The Stormraven Gunship is a relatively recent introduction to the armouries of the Adeptus Astartes. Indeed, as befits a bureaucracy as labyrinthine and cliquish as that of the Imperium, there are no official records to explain the vehicle's emergence. Certainly, the Stormraven began service and proved its worth within the Grey Knights and Blood Angels Chapters, and some records suggest that it was not meant to see broader use until the Adeptus Mechanicus were fully satisfied with its performance. However, in such dire times as these, when the fate of Humanity itself rests on a knife's edge, the Adeptus Astartes need every weapon they can find, sanctioned or not, and many Space Marine Chapters now field a handful of the aircraft alongside their more traditional strike vehicles.The Codex Space Marine Stormraven is nearly identical to the Blood Angels' version. The only difference is the four S8 AP2 stormstrike missiles it carries instead of the Blood Angels' S8 AP1 bloodstrike missiles. The Army List section of the book presents the Codex Marine Stormraven as being the base model while two smaller boxes indicate how those fielded by the Grey Knights and the Blood Angels differ (e.g., "Stormravens in detachments chosen from Codex: Blood Angels must replace their stormstrike missiles with bloodstrike missiles"). Unfortunately, the box for the Grey Knights' Stormraven neglects to state that their flyer is a Fast Attack choice; an oversight that briefly led to the model being listed in the army's Heavy Support section on GW's own website. This has since been revised through the Death from the Skies errata, which clarifies that the Stormraven is still a Fast Attack choice for Grey Knights. With this correction in place, there are no changes to the Grey Knights' or Blood Angels' Stormravens that aren't in the online FAQs.
The fact that a correction was issued almost immediately upon the book's release is certainly a mark against it, but it's better than the multiple errata that several of my $100+ engineering text books required.
It should be noted that the Stormraven has been nerfed somewhat with the release of Death from the Skies and the FAQs. The Shadow Skies/Skies of Blood rules enjoyed by the Grey Knights and the Blood Angels, respectively, have been changed to the generic Skies of Fury rule that also applies to Codex Marines. The new rule requires any units that jump out of a zooming Stormraven to behave as if they are deep striking, but with the additional requirement that any scatter will result in having to take a Dangerous Terrain test. (Thank goodness 6th Edition allows armor saves to be taken for failed tests.) I believe this means that GK Interceptors have lost the ability to land without drifting and Blood Angels jump troops can no longer avoid taking a Dangerous Terrain test or scatter only 1D6 per the Decent of Angels rule.
It looks like GW is explicitly discouraging the use of Skies of Fury as a combat tactic in favor of more orthodox deep striking methods. The only advantage of Skies of Fury is that it allows two units (the Stormraven and an embarked squad) to enter play at the same time. Other than that, your expensive Vanguard or Terminator Squad might as well be performing a standard deep strike. Most other units that don't have the ability to deep strike unaided can take a cheap drop pod that is a lot more likely to land your troops in the right place and intact. (Does GW really think that any Marine player in his right mind would load a Tactical Squad into a Stormraven instead of a drop pod?)
Now, I'm not saying that the Skies of Fury rule is worthless, just that it would be better named "Skies of Risk Management". Ideally, a Codex Marine or Blood Angel Stormraven assault would go something like this: the flyer zooms out of reserves and onto the table, shoots up a target unit, survives a round of shooting, goes into hover mode, allows a squad of jump infantry to disembark, shoots up the target unit some more, and then the disembarked squad uses its jump packs to assault the target unit while benefiting from the Hammer of Wrath rule. However, conditions in Warhammer 40,000, like real war, are rarely ideal. A Stormraven and its expensive cargo may very well arrive on a table covered with Vendetta Gunships, quad guns, Icarus lascannons, waves of Lootas, etc., where there's a high probability that the flyer will be shot down before it can go into hover mode and discharge its passengers. In those circumstances, Skies of Fury simply provides a way for troops to leave the vehicle more or less safely while the pilot contemplates going down in a blaze of glory. In other words, you probably shouldn't deliberately plan to disembark a squad from a zooming flyer, but instead think of it as a last ditch effort to save it.
Stormtalon
I bought the "Aerial Assault!" issue shortly after it came out, although I didn't even buy a Stormtalon until recently. Death from the Skies has changed the flyer's rules quite a bit, making the flyer even better but rendering the White Dwarf issue worthless to me except for the painting tutorial. For starters, the Stormtalon now has the unit type of Flyer, Hover rather than just Flyer as listed in the back of the 6th Edition rulebook. (That a vehicle characterized by vectoring engines and downward-pointing nozzles could lack the Hover type is laughable.) It has retained its melta-resistant ceramite plating and its wargear options. However, the points cost of the base flyer has been lowered by 20 points while the cost of the weapons upgrades have changed: the cost of the skyhammer missile launcher has been reduced by 10 points and the cost of the twin-linked lascannon and typhoon missile launcher have each been increased by 10 points. Despite the increased cost of two of the weapons options, the net result is that a Stormtalon with any loadout will now be slightly cheaper than it was under the White Dwarf rules.
All of the Stormtalon's special rules have changed; several of them drastically. The Aerial Assault rule allowing the flyer to fire all of its weapons after moving at cruising speed is completely gone since it was superseded by general flyer rules. The Stormtalon still has the Escort Craft rule, which is nearly the same as before, although the prohibition on escorting deep striking units has now been extended to outflanking units as well. The Hover Strike rule has been deleted entirely and has been effectively replaced (more on this later). Finally, the Stormtalon no longer has the Supersonic rule. This makes a lot of sense; the Stormtalon is clearly meant to be a close support aircraft, not a supersonic fighter, and wouldn't typically need the extra movement distance granted by the Supersonic rule.
The biggest change to the Stormtalon's special rules was the de facto replacement of Hover Strike with Strafing Run. Hover Strike was a unique rule that gave the Stormtalon BS5 while firing at non-skimmer targets in exchange for becoming a Skimmer type vehicle that must remain stationary during the preceding movement phase. This rule was horribly situational since the only time it would be beneficial to turn an otherwise hard to hit flyer into an immobile skimmer with a slightly improved ballistic skill was when a high value target absolutely had to die. Strafing Run also started out as a unique rule that was first given to the Dakkajet in June 2012's White Dwarf. Shortly thereafter, the rule found its way into the 6th Edition rulebook.
Like Hover Strike, Strafing Run gives a Stormtalon BS5 when shooting at any unit that is not a skimmer or a flyer. However, Strafing Run doesn't require that the flyer remain immobile or even to go into hover mode. In other words, a zooming Stormtalon can fire a twin-linked assault cannon and its other weapon (two of the options also being twin-linked) at BS5 as long as it's not shooting at a skimmer or a flyer. I know a lot of people laugh at giving a boost to a BS4 vehicle that can carry so many twin-linked weapons, but I've missed too many shots with a Razorback's twin-linked lascannon to scoff at the slight edge that the improved ballistic skill gives you.
As a side note, our Ork player, Jon, is seriously displeased that my Stormtalon (without upgrades) now costs as much as his Dakkajet while having better armor and an absurd ballistic skill thanks to Strafing Run. The fact that mine has only two hull points and his has three gives him little comfort.