Beta is... an alpha. Has a lot of errors. kill radius of the M67 is 5m, not 3 cm, 5.56 is weak, but not that weak. Ballistics absolutely need tweaking.
Also, noise and light discipline. No one leaves there IR lasers on to scale a wall. Bad guys have NODs, not a lot, but they have them. If there was that much enemy fire, it would go something like this:
You this is me, fire mission over. ######load of ordinance, grid ##########
Having said that, I have it pre-ordered. I am looking forward to it. If Bad Company is any indication to what DICE is capable of, the multiplayer has potential. I've always wanted to play JSOC units, but I will be a critic. Don't mess this up!