Yes, Ren was the big disappointment for me. Started out with just the right amount of evil awesome - ominous metallic voice and mask to boot. Then you find out that the mask is just cos he's a Vader-wannabe, and when he removes the mask it turns out he's a whiny teenager.
I preferred Kristensen.
Still, Ren may still up his evil quota in the movies to come.
Snoke was suitably dark tho - agreed.
The big surprise for me however was General Hux. The Hitler-esque speech he makes before firing the planet-busting weapon was fucking great. My favourite character. I like the way he overrides Ren when speaking to Snoke too.
So far as Abrams is concerned, by and large, yep, job well done. A lot of it I felt was copy-paste from Ep IV - esp in terms of desert planets, discovery of the force, and big round planet-busting weapons. But I guess he knows what worked the first time round so didn't vary too much in theme or setting.
Rey and Fin, were okay. Rey a little bit wooden, but she'll do. Wasn't too convinced about Fin's American accent either, given that he's such a London-boy, but it didn't detract from his character.
I preferred Dameron. He seemed fallible and human, and cool with it.