I have a chance to get a 20" iMac G5 for $15 at a local junk. It's a RevB, and when I tested it at the store it seemed to run fine. 20" is quite a big jump from the 17" model, and the screen quality is much better. But I am worried that it will fail early on me, I've heard a lot of bad stories about these G5 Macs. Anyone here have experience with these things going bad, and what to look out for?