Hit detection is definitely not identical. I'll admit, it wasn't perfect in MW2, but I can empty an entire magazine at an enemy in Black Ops from 20 feet away and get zero hits, then he can whirl on me and shoot 5 times and I'm dead. It's not a "well weapons actually have recoil" arguement because at that range I should be able to hip shoot at the guy and score all hits, it's just wonky.
The weapons sound like pop guns. I mean, have you heard the FAMAS? It sounds like a blender from hell. MP5 sounds like a kid knocking two plastic blocks together...bleh.
As for maps...I can think of 3 or 4 really good Black Ops maps: Nuketown, Summit, umm...maybe Jungle (although it's not particularly well laid out), and Grid off the top of my head. The list of those I dislike is pretty long though: Cracked, Hanoi, Launch, Firing Range (not sure why that map is so popular), Radiation, Villa...and the rest are so-so.
I'll agree with you, I'm glad to see Danger Close gone, but I can't say I'm much happier with RC-XD's.
It's not that I haven't adapted to playing Black Ops, my win/kill ratios are even better than they were in MW2, I just don't think it's as polished of a game.