I want a straight 3d Python engine that's easily obtainable for linux and easy to use. Soya3D failed for me because of the lack of documentation. I should be able to load common 3D models without an issue.
Panda3D is only other one I would really call an engine per se. There are Python bindings for Ogre, but I've heard mixed review of them. Unity can be scripted in Boo which is almost, but not quite, entirely unlike Python.
You can try Panda3D, but this is more a game engine than a 3D engine.
I don't know any 3D engine using python as a main language, since 3D applications are, most of the time, required to have smooth execution speed.
I didn't tried PyOgre either, but you might want to check out PyGLet, I don't really know what it is, but it looks great.
I love panda3d myself. super easy and well supported. Cross platform and whatnot.
Here's something I made with it: