BC2 was total ass at release, especially the server browser.BC2 at least it is polished. Vehicular's are not OP since release, no classes are truly bad unlike bf3. But the maps in bf3 in bc2 and i %100 guaranteeing you that mojority bf3 players would just quit and move over to it.
What class is bad in BF3? Even if there is a class you may be weaker on, at least you have an assortment of PDW weapons to choose from to suit your gaming style.
Just the fluidity of movement and player control in BF3 alone is enough for me never to want to play BC2 again. Even though there are tons of other reasons, for example Bc2's wallhack spotting and retarded revive systems.
And vehicles should be overpowering to infantry. Just ask this guy:
