The map design is better in Crysis 2 as well, and it seems like i stay alive longer after spawning. Which brings me to the balancing of both games. I think c2 is also balanced better with the way the killstreaks are used. Blops, seems like the ultimate goal is camping for enough kills to get a chopper gunner called in, whereas in c2 the ceph gunship is strong, but not as over powered as the top tier kill streak awards in Blops. This may make it less fun for kill farmers, and i think that's a plus.
The only thing blops does have going for it, is the number of people playing, but then I guess the c2 community might be better off for not being overly large.