M4A1, dawg. 600+ kills with it, closest weapon behind that is 300 or so. That and the M16 are severaly underrated. M27 IAR is pretty sexy.
I even like the AK's, honestly. They just feel really good, even if they may not perform as well as US faction weapons.
Destruction isn't really "better", as it's improved in BF3, though not to the extent that I thought it would be (still not really dynamic/physics-based). BC2 had a lot of maps that were defined by "Here is land with structures on it. Blast through these structures to the next point." There were maps that literally had you fighting in and out of wooden hut-things. For better or worse, BF3 focuses more on "actual" locations and setpieces rather than plopping down random buildings.
I think the Rush maps in BC2 were overall great-good, but the ones in BF3 really aren't "bad" either. I haven't played enough to give an honest opinion yet. Most CQ BC2 maps were a fucking joke, though, and just as bad or worse than any in BF3 (okay, maybe not Metro).
Yeah, they screwed the pooch on squads, but I like BF3's class system a lot more, and it would be much better if they better balance the Engy class and buff Recon points.
Vehemently disagree with the shooting mechanics. I feel BF3's outclasses BC2's gunplay in every way, shape, and form--it's really hard to go back to BC2 for this reason alone.
They need to bring Port Valdez (Rush), Arica Harbor (Rush), and Harvest Day (Rush and CQ) to BF3. I even have guilty love for Valparaiso and Isla Inocenes Rush and wouldn't mind seeing them.