I came around full circle, sort of. I am back to the kensington expert. And I am using it on the right hand side. My elbow is still not quite right. Otherwise I would be using the orbit on the left hand side of the board.
The expert is one smooth trackball. Its very slick. I have a kensington turboball(which was NIB, but without the box) and a kensington turboring. These are both nice mice and I would be using them but they are opto-mechanical. They use the rubber wheels and I am sorry to say that they are no where near as smooth as the expert.
I think the expert is the king of all trackball mice. : )
I will stand around now, and wait to be flamed.
As for the cherries, I still love my brown cherry filco. But right now the black alps is pretty awesome. I have been using it for 3 weeks straight now. And have no desire to swap it out.