Sorry to resurrect an old thread, but I noticed this while searching for something else and wanted to ask clarifying questions:
it doesn't really offer much beyond Blitz3D, and is considerably slower.
Well it offers programmable shaders, which is a biggie for just about any game developer. It's also cross-platform, which matters a lot to some people. I didn't think to check it's rendering speed though (I know, pretty obvious thing to check, it just didn't occur to me); is that what you mean by "considerably slower"? I've been considering switching to Panda for future projects, but now I better go run some tests where I look at the fps when I throw massive numbers of models at the engine.