I dont understand this comment. What are the large amount of buffs? Tyranids can't use the new fortifications, can't use allies, new wound allocation system greatly hurts horde "cc" armies, have no AA weapons at all, can't assault on outlfanks (this is universal, obviously but still very much effects how I play this army), now have to endure Overwatch in addition to going last in CC when assaulting into cover, the nerf to fleet which sees all armies gain the same threat range for CC, etc. It's like GW put in all these cool new features into 40k then looked at Nids and said "NOT you Tyranids, you go sit in that corner and think about what you have done".
The only decent things I see are leaving their Psychic Defense as is, huge boost to flying MCs and Broodlords being able to switch out their garbage powers for two from the deck (which is VERY cool). Also, I am interested to see how Zoans do being used in a support roll as they can switch out their powers for the decks also (dont have to cast the same thing).
In regards to the FAQs to say I am underwhelmed is an understatement. They just have a bunch of generic "Pink 6th ed Speak" at the start and then just the old, 5th ed ones. The only one that is even remotely decent is for the book that was basically written for 6th ed and that is the Necrons. Addresses all their funky rule issues, addresses all their weapons and what AP they should be, etc. which is great.