To follow up on my last post, Temperature Monitor and iStat Pro report the same values on the dual 2.0GHz G5, unlike what happens with the dual 1.8. And new heatsink compound, which has now been applied to the dual 2.0 GHz machine (it only takes about 45 mins. to take apart, do the deed, and reassemble) makes no difference to the CPU temperatures, which still hover in the high 50s/ low 60s Celcius.

On the upside, the fans are not roaring and the machine seems perfectly content. I guess I'll leave it be.