Well, technically there are no differences between Panda and CrystalSpace in regard to what they can do. The differences are in how they do it, how well and how easy it is to achieve good results. I’ve been using Panda for some time now and it still amazes me how easy it is to get things done with this engine (no, they don’t pay me 
).
As far as OGRE goes, that’s a completely different story than CS and Panda. While these two (especially Panda) are game engines in full sense of this term, OGRE itself is basically only a rendering engine. If you want anything other than that – like collision detection, physics, GUI, AI, sound, you name it – you have to pick up one of the additional libraries available. They seem to be quite well documented (well, OGRE is arguably the most popular OpenSource rendering engine with a large community), but that’s additional work you need to do and it’s not as reliable. With Panda you just install one self-contained package and you’re good to go.
Also, most importantly, you can be sure that what comes with Panda will work with Python. In case of OGRE, Python support is added in a similar way as in CS – as an add-on installed separately – and you can’t expect everything from the OGRE’s additional libraries to be python-enabled.
That’s basically what I meant by “not ready to go”.
On a side note. If you want to make an FPS, then perhaps you would be interested in my code snippet for ODE-powered FPP. [ODE Middleware).