I recently purchased a dual 1.8 G5. It was defective out of the box - had the fans on full blast problem. I called Apple to complain, after trying the recommendations on this site (reset PMU, etc). They referred me to my local Apple VAR, which also does service. They were able to fix it, after having it for 3 days. The tech said that he had to re-seat the processors, and run the calibration program again. Whether all that was necessary, who knows, but now it runs great! My conclusion is that the refurb process is not as stringent as Apple would have you believe. It's surprising to me that the machine could leave Apple with the kind of problems it had. However, I was pleased with my post sales service (although the delay was killing me), and now the machine is folding for me 24/7. It's very quiet, particularly compared to my old Dell piii, fast, and fun. I'm pretty sure that I'll be buying applecare, though, in the next year, just in case.