I've experienced similar "jitters." I don't notice it too much when running around outside - although it does feel a little choppy - but when I walk in buildings its almost like I'm desyncing constantly.

I use trackir. It multiplies the effect many fold.

I can confirm this. FPS is a bit lower than before but still acceptable (like 60 fps instead of 100 fps), but jitter/jerkiness/choppiness is horrible.

I am getting a major version of this playing on the AU experimental server. My ping is 50-90ms. Symptoms are total loss of control of my character - it spins and flicks in all directions for an extended period 30 seconds +) and also moves in random directions. At times I quickly reverse to a place I'd been in minutes before. I have experienced this 3 times today after playing for 60 minutes.