Lately, I've been doing all robotics works exclusively on Ubuntu.
Eclipse makes things easy for the Axon/AVR, and Webbot's Designers also help a lot too. For receiving data from the Axon, I just use gtkTerm, or whatever other terminal I feel like.
I've done some designing with Q-CAD, and I would trouble myself more with 3D designers, but lately, I haven't had much of a need for that software.
I use EagleCAD as well for circuit design.
Currently, the only reason I can see myself using Windows anymore for robotics is just to use Google Sketchup...