I remember giving MachStudio a try when it came out and it SUCKED. It looked like a renderer written by someone who had a PhD in mathematics, but who had never modeled or animated anything in their life. The interface was just horrible.

If you're looking for free, Evermotion made NOX open source at SIGGRAPH: http://www.evermotion.org/nox

At least they're still in business.

-Paul