Just got it.. Seems NICE:!

Gonna do some more testing tonight, but it seems like just as big a leap as between mx500 and mx510 from what ive felt so far :D

1600 dpi seems to work even if you move your mouse really fast, as fast as i move anyway. 360 in 0.05 sec over 15cm or so.. Don't think it has any accel; gonna check it later..

Now i go for a zzzwim :)