I have tried both on my Mac Book core 2. I have to agree I like Parallels UI better than Fusions. The tests that I have seen done were on a Quad core Mac Pro. Hardly the normal system for most users. I am not sure speed is a issue for what can be really done with ether Parallels or Fusion. I think stability is more of a issue here. Plus, support for those that need help. If you really need speed for gaming, Boot Camp is still the only real choice. Native OS running will always beat out Virtual software. But at $160 to $200 for Parallels or Fusion and a copy of Windows. Due you want to spend that for access to IE or Outlook express? I find after booting Parallels and starting Windows XP I could have done the same thing starting boot camp? I personally don't switch back and forth that much.