I have Truespace 2, and I even use it from time to time--I find it to be
relatively user friendly, as 3D programs go, but still it has a learning
curve to it.
They do have an upgrade (Truespace 3) but I haven't bought it yet.
In general I really like it, but I wish I could find a class to train me.
There is a terrrific book out by a friend of mine, called Caligari Truespace
2 3D modeling Construction Kit, by David Duberman, and published by Waite
Group Press, 1997.