I can understand switching to a rifle forcing you to stop moving, but having to switch to the pistol is something which is usually supposed to be done as an alternative to reloading--and I'm finding more and more, in situations where I would swap to the pistol, I'm just reloading and getting shot...Since the switch weapons animation is so slow and since switching to the pistol is virtually pointless since you have to stand still. As for realism problems, when I'm airsofting, I do this all the time--your rifle's on a sling, and you just let it drop, pull up the pistol [from the dropleg holster which is attached to every combat rig] and fire. And you can do this while moving and hiding and generally being mobile.
Anyway, I still really like the game so far, but since the motion is so much more...nice, I feel like I should post this here so you guys know what else you could do to make the game even more fun to play.