I have a Cooper 22 in 22br, and its a great cartridge. Mine is very accurate, probably the second most accurate rifle I own, next to a 6ppc br. rifle. It has been accurate with anything I have shot in it, but the best accuracy by far is with the vv135 powder and a 52gr bullet. I don't really think you will see much difference in accuracy between a properly loaded 22br and a 22ppc. velocity is good, just under a 22-250 and not by much. My brass is a little of a pain to make as the rifle has a tight neck, and I have to turn them. other than that no problems with the brass. only use the Lapua now, but have used rem and norma. If I were you I would snap it up now.
Barry