USNA managed to fit the huge scope of 40k into a single ruleset, which is quite a feat. Their approach enables you to play characters such as underhive scum or Ork Boys up to the glorious (Cchaos) Space Marines, Inquisitors and Rogue Traders. It leaves you with a freedom of choice in regards to the play-style that is fascinating (Eldar Corsairs or Chaos Heretics, anyone? You can play as such!). The rules are comprehensive and as a GM I have never managed large quantities of NPCs quiet as streamlined. The shifting mechanic gives the players a good ammount of influence on the outcome of their actions and USNA made sure that no skill feels obsolete. The combat is gritty but rewarding (and characters can make use of non-combat skills through "Interaction attacks" which influence the fight as well and add narrative moment).

Overall I like USNA's take on the 40k Universe, that is why I did not vote 2 stars.

But the rules suffer from poor editing, that leaves you pondering. There are a lot of mechanical inconsistencies that give the impression that at one point USNA decided to further streamline the rules but failed to check all the cross references for consistency. Which in turn ruins the whole streamlined ruleset like a deep road bump on a German highway. To me as a GM whose players appreciate my fair application of the rules and who do not like arbitrary rule interpretations, this can really ruin the flow. USNA are eager to clarify those rules problems in their forum, but I would rather not have to check a forum repeatedly and keep a stack of notes next to my rule book that are not story related.

So in the end, I feel like I purchased a (late) beta product and that is not what I ordered. I'll be happy to improve my rating when the PDF gets updated, but right now I can only recommend to buy the game with caution. I have hopes that since I have a PDF it will improve in the next months as it gets updated. But if I had bought the print version in the current state of the editing I'd return it immediately.

TL;DR: The scope and the approach is rewarding. Nevertheless, the rules are poorly edited and leave the impression that this is a beta product.

EDIT 31.10.2018: Our group enjoys the rules very much and in the past weeks(!) since I've written the review USNA has taken the input of the player base very seriously. Keep it up! :) Even though the PDF has not been updated yet, I feel inclined to improve the rating.