I just picked up one of these from Newegg the other day as I have been experiencing wrist pain a la RSI from years of using traditional mice (I know, I know, trackballs/points FTW).
It has an interesting shape in that it feels like holding a baseball or tennis ball while in use. The wrist is rotated about 80 degrees from a regular mousing surface so that side to side movements flex the wrist on the regular joint axis rather than side to side. the thumb rest is a gel like rubber that feels good on the hand and provides a nice, grippy surface for extra control. It has a smooth scroll wheel which I like when I play the roll of spreadsheet jockey or reading web pages (I prefer the tactile scroll wheel for gaming). The scoll wheel also allows for sideways scrolling; again, nice for spreadsheets. The mouse also has forward and back web navigation buttons.
So far, the pain I had been feeling in my wrists has subsided, but it does take a few days to get used to using it since it is not the usual position for the hand vis a vis a traditonal mouse. Up and down movements require the most adjustment since it takes almost a whole arm movement to perform.
The mouse is wireless, and I have not had any problems with reception. I wish it were a rechargable mouse like my Logitech MX 1000, but, instead, requires AAs.
I have enjoyed using the mouse thus far, and may try out a track ball if I do not feel any significant improvement. I will try it at home for a while first before using it at work. Click the link below for the Newegg page to see pics.
http://www.newegg.com/Product/Product.aspx?Item=N82E16826105221
