I bought gameSpace (full version) a half year ago, and I love it. The interface takes some getting used to, but I guess that is the case for every 3D application out there. But the interface is very consistent, so you learn quickly.
The community on http://forums.caligari.com/gameSpace
is extremely helpful, which is a big plus.
Before I bought gameSpace, I used Wings3D + Milkshape + Lithunwrap, and although they got the job done, I find the workflow in gameSpace is much faster.
For me it was worth every penny.
That said, I must admit that I am primarily a programmer and secondarily and "artist". But you can see two of my models at caligaris forums:http://forums.caligari.com/gameSpace/showthread.php?s=&threadid=373&highlight=ziggurathttp://forums.caligari.com/gameSpace/showthread.php?s=&threadid=1035&highlight=jumpnrun
And the .COB file format is easy to parse. I have written a JOGL based COB-viewer, that can display an animated model.http://forums.caligari.com/gameSpace/showthread.php?s=&threadid=997&highlight=jumpnrun
But try out gameSpace light and make your own opinion. I think it is very generous that they have released a fully working version without watermarks and cryptic fileformats.