Modern Macs are fantastic computers, in my experience. After always using RISC OS and realizing I needed more then could be expected of a RO machine, the choice was obvious to me: a Mac. Why? Mac OS X is very powerful, yet easy, uncluttered and pleasurable to use with the most resemblance to RO I've yet to see elsewhere. Plus their hardware is pretty nice. Apple and Acorn have a history together and I've always been of the opinion that if I'd need an alternative system, it would be a Mac. I haven't regretted this decision for a microsecond and it's a great partner to my RiscPC.
Indeed jess, it is a great shame VA hasn't pushed on and completed their Mac version of VRPC. Now that all new Macs have Intel CPU's inside them, I suspect it could be easier to port the code over to OS X. I'd hate to run Windows on a Mac to get to VRPC, because I hate to run Windows.