I use Softimage on a daily basis with MoI. Works very well and is better suited to single users and small shops than Max and Maya IMO. Not as hard to learn either!

There's a handy plugin for SI that lets you drag and drop .obj files so transfer from MoI is fairly quick. If you're going to try AD products I'd suggest trying SI.

Here's an image I just completed with it and some MoI help in modeling:

http://www.actionart.ca/images/ClashOfTheTitans.jpg