Does anyone use them, or have any recommendations?

We used to have a logitech jobby 10+ years ago. I remember being able to use it quite well. Im thinking of getting another as I hope/think that it might help in terms of the RSI I get from using my mouse constantly, changing mice helps, but it seems it always comes back after some time with the new mouse.

The trackball I had before was a big logitech affair which wasnt really a thumb trackball, I think the mouse buttons were on the left with the red ball bang in the middle. Do you think thumb ones are better/more comfy?

I used to swear by the MS trackball Optical line, had a few over the years.  However they no longer make them!

Ill likely get an M570 when theyre out if I can find the release date and its not "next year". I need to sort something out pretty sharpish but its the only one I like the look of the design on. Will have to hunt around at the weekend and try Pc World and Staples and hope they have some trackballs on display to check how they fit in the hand.

theyre out now if you can find them  I think.. at least they are listed in american stores

Logitech website still lists them as preorder though?

FYI Whereas the initial reviews in Sept said "Sometime this month" theyre now saying sometime in October.

I can remember playing MechWarrior 3 with a keyboard/trackball combo. It worked quite well I think. I think I remember thinking when I swapped back to a mouse back then, that the mouse was easier, but that I found it less accurate, in the sense of overshooting what I wanted to click at the same speed I was using the trackball.

Well its arrived. Its nice and comfy though I think its going to take a bit of getting used to. Not sure if Id have rather it was finger instead of thumb controlled. The tricky bit is making the motions smooth, I keep overshooting or trying to click on a specific point, letting my thumb move as I am clicking and just nudging the ball up a little and missing!