My thoughts?
There's no way I would buy a G5. All the ones I have worked on (30+?) have had some odd issue or another, particularly the iMacs. If I had to go PPC, I would go with a G4, MDD or Al PowerBook. For the most part, the G4s have been very solid. My MDD here at work is still my primary Desktop, and my (upgraded) Quicksilver '01 is still my primary Desktop Mac at home.
But.. at this point, there's no way I would go with anything that wasn't Intel. I already feel all my PPC Macs getting long in the tooth. As I've gotten used to the speed of the Intel Macs, and Tiger/Leopard on Intel Macs, it becomes more and more frustrating to work on PPC Macs. An issue that won't get any better with time.