WF Fusion is... hmm. Quake 2 physics in the quake 3 world. So basically if you didn't like mapping in quake 3, you won't like mapping for Fusion... they are 97% similar. That said, there is nothing preventing you from making your maps less bulky these days. I get 1000 fps in Fusion. The general quality of hardware today is definately much better than it was when Quake 3 first came out. You can use significantly more curved surfaces and such to make your map feel less blocky. The size though... that is the same :/