That's just how the games play. BC2, for example, has slower gameplay than BO2 simply because the games are structured differently.
No it's pretty much only on consoles which can only run BC2 and BF3 at 30 fps max. I mean, there is a definite feeling of bulk but even then on PC movement is a lot more fluid. That's a lot more apparent in PC BF3. PS3 BF3 feels and definitely looks slow while on PC it's an entirely different experience.
And I'm going to have to disagree with you that it's something I wouldn't notice while playing. Playing CoD is a night and day difference to me in how it runs visually but even more in how it handles, and I don't even think it's a locked 60 on PS3. You're definitely right in that fluctuating frames/sec is a bigger issue, but 30 vs 60 fps is a big difference in performance too. For me, it's a big enough deal that it's not being pushed as the new standard.