I guess OP is focusing on the big hitters here, so to steal the list earlier and focus on the ones I've played, I'd say a solid 7.5. Most of my issues are around creative decisions rather than the proficiency of the studio's. I think they have a couple of near perfect IP's, and then a strong, smaller list of games with competent mechanics with high production values.
Naughty Dog
Uncharted 4 was not an Uncharted game (to me). Lost Legacy redeemed a lot of bad decisions. Haven't played TLOU II yet so it sits outside my opinion.
Insomniac
Pretty good debut IP with a license to move units. Probably place it around the same as I:SS. Didn;t really punch above Batman for example, but was solid and enjoyable
Sucker Punch
I:SS was a decent jump but still has that 'studio trying to break into AAA space' feel and mechanics. Hopefully GoT addresses these but I'm starting that later.
Guerilla
The most pleasant surprise from new IP, though not without issues. But new IP, change of genre you can cut the developers some slack. Easily the most impressive debut IP for me. Think this will become a tentpole next generation.
FROM
Bloodborne was a great game in the early portion of the generation and probably one of the first must-have titles.
SSM
I don't feel the new God of War did enough really. Between this and Guerilla for example, I think Guerilla handled the conceptual transition to a completely different playstyle and genre much better. I think it would have been beneficial to make this a completely new IP.
Evolution
is closed now so.......driveclub did a lot of the visual stuff really nice, but the inaccessibility of it now, plus the bad launch and the 'free game' thing really hurt it.
Supermassive
Until Dawn was fun. I felt it relied a lot on its genre to shift units. There's no real big difference to this and a David Cage game really.
RAD
Despite the shit The Order 1886 got, I enjoyed most of it. Aside from one boss fight in the warehouse I enjoyed my time with it. This could have been more though.
David Cage
He kind of gets to do his own thing now, and you expect a title or two from him. I've enjoyed all his games. Just take them as they are really. I still don't think he's made anything as gripping as Heay Rain though
Polyphony
Again, GT:S gets a lot of shit, but being honest I like the pared back game more. And I definitely prefer the circuit experience to open world.
Housemarque
Loved both Alienation and Resogun.