I got an G5 @ 2.7 GHz and so far there is no problem with it. But yes, one day it will start to leak and then I have to get it fix (expensive) or throw it away.
The 2 GHz models are plentiful, fast and pretty cheap. If you can find a 2.3 GHz (the fastest without water cooling) it would be a very good buy.
I'm very happy with my G5, even though there are some slight compatibility issues. I think the raw power makes it a lot more joyful to use than my slower G4 Ibook and Powerbook.
Like Krashan said, it depends on what you want.
What kind of compatibility issues>?
