Playing sense end of 4th, Competitive Nids for 5th and DE for fun, 6-7th was only DE for me. I may not be the "most" experience here, but the community where I play have many players that are highly competitive and played sense rouge trader days, we always talk about all new codexs that come out, look at the pro's and cons' comparing to others and making lists ideal for them, I've learned alot from these guys and many hours of research online... With that said I believe the new DE book took a step back in some places but took a step forward in others.
Alot of our SC were removed, but this seems to be the trend, not just for DE. Many of them wasnt even played and a couple can still be "created" with wargear.
Each HQ I feel now are in a niche Roll, Archon now is in the Shooting and DSing Roll, also able to take a court with him and a Vehicle makes its more useful in other ways than a CC moster/ic hunter.
Over all the HQ choice I feel for the New DEX are fine, the new DE codex isn't meant to be Hero Hammer.
The worst part of the book IMO, only really 1 playable troop choice. I feel wyches took a step back, but warrior took one forward.
Nothing else to say but there Isnt much flavor here and I see warriors being VIP's of troops.
Turenorns and Incubi getting cheaper is a huge plus, Grots being strong and better is a plus too, and Mandrakes are now playable. The elite took 2-3 steps forwards for sure.
Wracks: 5man now with more options is fine, they are a different niche roll than before, I can see having unit or 2 in venoms with some of the upgrades could have alot of synergy to some DE lists. (and thats why I said they are Niche roll now)
Bloodbrides: in the same boat as Wyches, other are just better.
The creamy center of DE. Fast Attack got insanely better, other parts of the book might be sore on the eyes, but FA is the hero in your favorite action movie.
The 2 Biggest things are Scourges are now good and Reavers changed rolls.
Scourges: Cheaper and can take 4 heavy/special weapons is very nice, 5mans with 4 HWB's is a strong unit now.
Reavers: I feel they are actually better in some ways, for less points you can take 2 Caltops and 2 HL's for about 20pts more than the old unit can also have Champ with Agoniser. Or keep them cheap and just take unit of 6, 2 HL's with 2 Caltrops, If you can charge the back of a vehicle you will do some damage.
Razorwings: Moved to FA makes them desirable now. You can keep them cheap as is for AI, or upgrade for 10pts to give Lances.
Beast Packs: I feel they are in line now, before a 25man 4++ save unit moving 12" was actually a little to strong, specially sense I took a Farseer on Bike with them, and God help you if I got invisibility and you cant deny it. GW is trying to make Death stars a thing in the past and Im happy for that.
Compare to other FA they dont seem to be worth it, but if they arnt posing a threat, easy to hide in cover and able to get to places, they may have a roll for some players lists still.
Hellions: I see them as Wyches with a 12" move. Not really that great, but can DS pop a few shots off and most likely will die. I feel a few player will make them work, but its an up hill battle for them.
Void bomber: Many seem to like and many feel its over price, I feel its over priced for taking 1, its a vehicle that I feel you need to have a list synergies with them to make them good.
Ravager: with a Points increase and rules decrease, they are still play able, but now with Scourges/Reavers doing AT taking them as Cheap as you can to bump out MANY S5/AP2 shots is something DE never really did. They have havoc's, Centurions, Terminators etc.. a ravager or 2 can put the hurt on these units and fast. I feel Dis Cannon Ravagers will be played alot more.
Talos/Cronos: IMO they got the Buffs they needed, can take in units and support each other/other units more effectively, they are a unit you need synergy with and for most players a Niche roll.
Power From Pain
This is a great step forward for me, it really makes the DE feel more fluffy and gives DE more survivability for staying in battle longer, No longer do we need a kill to get FnP.
Look at the book as a whole and having the Coven book to help it, the Basic DE book definite feels like Pirates raiding out of no where army now. With the Fire power shifting from one part of the book to another, I feel many players arnt ready to adopt yet.
I can see many new competitive list being used and not the same style boring static Gun and Boat lists all the time.
I feel some Eldar allies will be a good choice too, with FA transport, some eldar units seems to be able now.
Over all Im happy with the book and Find it took a Step forward.