Thank you for all the input so far. I have used Macs from time to time for different reasons (did a Photoshop tutorial on one, did some digital storytelling prep on another, have borrowed friends' laptops from time to time) and I'm fairly computer savvy, in that I've had computers for years and have only rarely had the benefit of manuals. Got a brother (and a husband) who can find his way around fixing most PC problems.
And I'm thinking of buying new, not used - specifically, a high end Mac Mini with the intel chip so I can dual boot, or a Windows 7 PC with loads of memory.
Still not sure .. got a few days yet to make up my mind!