I don’t think Panda3D is slower then other engines (and what other engines would that be? Are there any tests published anywhere?). Why should it be? Because of Python? The parts that need to be fast are written in C++, so even if there is some overhead on calling compiled code from an interpreter I wouldn’t expect it to slow down anything more then 1%.
If you can make good models and shaders then panda can use them, and I don’t think there’s any other engine out there (be it commercial, free or free-ish) that could use those models/shaders (much?) more efficiently.
Oh, and for an example of what p3d can do - do check out this: Deferred Pipeline w/ Physically Based Shading