VMWare is faster then UAE because VMWware doesn't have to emulate an entire processor architecture. In theory, VMWare doesn't have to emulate enything, just simulate a normal x86 computer. This also explains why VMWare wont run MacOS or anything else that doesn't belong on the x86 architecture. UAE on the other hand, does emulate stuff. It maps M68k processor calls to whatever processor it's running on. It's also far more tricky regarding access to local system resources because of all this emulation.
As for VMWare making a nice disaster recory solution, I agree. Also, when given limited resources, it also makes a nice solution for shared hosting. Just dump a cheapo Linux distro on a good machine, run VMWare on it with and give people full Administrator/root/whatever access to their own virtual PC. If they mess up, worst that might happen is their virtual PC kicking the virtual bucket.
