left hand: Mionix Avior SK
in front of the keyboard: Contour Rollermouse Free2
right hand: Mionix Castor or Elecom XT2
Each is somehow imperfect.
Avior's side buttons rattle a little bit. The shell is "flat" ambidextrous, thus there's a bit too much hand pronation at times (thus multiple pointing devices). Configuration options are underwhelming, hence I've only swapped left/right button actions… I miss Roccat's EasyShift. Luckily, I finally have a Kova Pure in the mail (after my previous attempts at buying it failed, due to being out of stock or the vendor messing up).
Castor is alright for the most part (as a "dumb" mouse), except its coating somehow feels gross, when I'm a bit sweaty. I wonder why my Kone Pure [Military/Color] sits in the closet…
At last but not least, the rollermouse. Free2 feels flimsier than the old Pro, but about everything else is better. Except the default button mapping is completely stupid, and can't be changed without proprietary drivers for proprietary OS'. The middle large button serves as "left doubleclick" instead of "wheel click", and while the new wide wheel is pretty good, its lack of tactility while scrolling leads to accidental scrolling, when attempting to click instead. Left-/right-handed orientation can't be swapped with a DIP switch or something. And Copy/Paste buttons, that send Ctrl-C/V? Seriously? O_o Yeah, and calibration for a triple-screen setup is weird.