Have been going though valids and pendings at WCG comparing the CPU Time / Elapsed Time on the 2 PCs and since I made the priority change the numbers have gotten better and are better than the one with no change. The difference is small but just changing the priority using cc_config.xml on a dedicated cruncher seems fine. When I ssh in I can see no difference in responsiveness. I would not do it on a machine I used for other things. I see no reason not to do it on a dedicated cruncher.

Still have no idea why my top results are different though. But even dropping from 19 to 10 in the nice column does shave off a fraction to a full second on a 2 hour work unit. A very few 2 seconds. I added the setting to the cc_config.xml on the other PC as well.