Well, we just did a very crude little test of Unity's PC build, and we're pleased that its performance was right in line with our old pc-only engine. It still remains to be seen what will happen when we bring in the rest of the geometry, code, and a touch of particles--but so far the PC build is looking great. The amazing thing we found was how little RAM it required. Barely any!! Again, just a very simple test, but very encouraging.