I havent played much, but I have to say its far buggier than I thought it would be. Animation and movement glitching is all over the place and there are severe collision issues with both terrain and objects (firing an RPG into a building only to have it go through the wall and kill an enemy soldier without actually damaging the wall was bad looking).
The actual combat was an up and down experience. Overall, I enjoyed the new deadlier weapons. Combined with re-introduced proning, it makes for a more cover-to-cover gameplay rather than just plain running as in BC2. But at the same time there where plenty of moments when it was just stupid. I especially remember a time when a M249 enemy came around a corner. It literally took 0.1 seconds for him to kill me. I just heard a single shot and bam I was dead before I could aim my gun at him. This just doesnt happen in BC2. Damage is all over the place... I dont know if its network lag or something but when I shoot they always seem to eat my bullets and spit them back.
I really hope the combat will be tweaked and improved. Its good but it doesnt feel solid.