[AUmrysh]

I never really felt much motion sickness from it, even in TF2. I didn't really enjoy playing that way, as I felt like I lost some of the control mouse+kb gives, but it's certainly immersive.

petercooper hit on the big problems: the lenses fog up quickly and the low resolution in the dev kit is distracting.

Also, in some games like surgeon simulator 2013, there is drift which means you're spinning slowly in a circle to keep looking at the same spot. It's horribly frustrating, and ruined the (already frustrating) experience for me.

Unreal works very well with it, however. I think any game which doesn't rely on fast transformations to the perspective will benefit greatly from the immersion the retail Rift brings.