Yes they look like plastic dolls, but that doesn't mean they look any less detailed than any other game. in fact they are well above the rest.
They aren't as detailed, period. I also thing they're quite mediocre and very far behind truly outstanding character artwork like what we see from Naughty Dog.
Crysis 2 used tessellation for all characters,
Unfortunately it hasn't.
Other strong examples include Metro, Call Of Duty Ghosts and Hitman Absolution.
Ghosts is another good example of the doing very, very little on its own, without displacement mapping. I think they only use it on faces and the first person weapon's certain parts (like scopes on sniper rifles).
I also don't believe Hitman has any tessellation either