I wouldn't argue about this being an improvement over 4 and 5 in terms of control, Agent D. The characters are much more responsive when compared to the shambling tank messes of the previous games. That said, they slide around the environment like Agent 47 in Hitman 2, and it feels terrible when trying to avoid zombies on the ground. I'm not sure how they managed it, but RE4 still has the best shooting mechanics in the series. RE6 just feels too slippery when you consider the precise shots necessary to pinpoint weapons, legs, etc. As for the melee stuff, I just can't seem to figure the whole thing out. I end up attacking too short or running straight into the enemy and missing my chance to do some serious damage. It wouldn't bother me if it was a compliment to the shooting, but you have to use the melee mechanics otherwise you run out of ammo in about thirty seconds. I'm glad they're using a stamina bar to keep you from spamming those attacks, but it still feels awkward and counter intuitive to me.
Dead Space 2 just plays better, and Isaac feels far more responsive than any of the cast in RE6. I'd rather hold a trigger to run rather than holding X and potentially skipping into cover, or accidentally quick turning, or maybe leaping over a box.