IMO trackballs rule! They put less strain on your wrist, can offer better precision, and they take up less space. That said I think alot depends on the quality of the thing, I have never bought anything other than Kensington, but they seem to make the best- their driver software is comlpetely customable for any app. I have a Kensington Orbit trackball, it only has 2 buttons but it has worked flawlessly for over 3 years, pretty good I think! Kensington stuff does cost a bit more, but you get what you pay for [img]smile.gif[/img]
Check em out
http://kensington.com/html/1436.html