Well, for what I'm wanting to do, a deformable terrain would be merely icing on the cake.
Doesn't PhysX support dentable meshes?
Also, I don't like Advanced Terrain because you can't tile the texture on it. It's just a big, screwed up pixelated mass with a single detail texture on it. Detail textures for grass are totally inappropriate for dirt and vice versa.
Nothing I say is intended to be rude. My autism means that I do not know what is rude and what isn't rude. I apologize if I seem rude. It is not my intention.