Yes the tearing is huge. I've never noticed any tearing before until Doom 3. I've got a couple hours in with Vsync off and the tearing isn't as bad as it is in the beginning. Well, perhaps I am used to it now. Anyway I don't really notice it anymore.
I'm in Alpha Labs 2 right now and have to say the experience is just getting better. Yes, the gameplay consists of pop around one corner, fight off baddies, pop around another, fight some more, rinse and repeat. However, I am totally digging the atmosphere of this game. The setting. The ambience. The enviroment. Perhaps having this 5.1 sound system is making a big difference. I can hear enemies behind me, to the left, to the right, etc. It adds to the tension of the game. Of course, some people might get bored, but doesn't it raise your adrenaline a bit when you two around a corner and see four beady red eyes staring at you in the dark? I've been known to bash ID in the past, but this is a fantastic effort on their part. Can't wait to play some more tonight.