Rhino vs Truespace?

Has anybody done a serious comparison of Rhino vs Truespace 4 or 5?
Or know of maybe a magazine article that did a fair job of side by
side comparison? I was reviewing the Truespace web site today & saw
that they have an older version for as little as $49! While the
version 5 with support for IGES, STL, SAT, etc is about $894, version
4 is selling for under $500 and that seems to be a pretty good deal.

http://www.caligari.com

http://www.rhino3d.com

Best Regards,

Fred Smith
IMService