Agreed I'd love to see a good MIPS desktop come about - but until then my 2.5 Ghz G5 quad is trucking right along - just checked the cooling unit the other day, its in fantastic shape. The case has seen better days, but thats just superficial.
I have an SGI Fuel running at 600mhz and it works very well for basic things - but if I need the oomph my G5 can take it. I also have a dream of getting an SGI Tezro, but that will be when I'm in better finances.