also been using an evoluent vertical mouse for about 3 years. Probably about half the office use them now.
Using the classic gaming mouse at home, but at work I have been infected with our office's vertical mouse fanfare.
It is definitely something I recommend for long monotonous sessions, certainly more comfy.
Doesn't matter which manufacturer or model, the vertical nature alone makes quite the difference.
edit:
In start, using Vertical Mouse
haha, just read this after posting.
Apparently this is some universal consensus among 3D package users...