My iBook is running VPC under X. I have 192 MB for all of my virtual Machines. (Win 95, 98, 2000, NT, XP, and Mandrake Linux). It is faster than the PIII 550 that I have here at work. So much so that I took down the PIII today and put it in the closet! Now, I just have my silver bullet sitting on my desk!
Oh, and one thing oldmac. I have to run this so I can see what my clients see. I have never, and I mean never, not in two years of using VPC gotten a blue screen. Can you say that about your machine?