The A1G4s are working just fine (one here, now) at
full speed WITH dma and so on, but the cooler that
came with the mobo was crap really, and some of
them weren't even mounted properly (which ofcourse
caused instabilities for some people).
..and the G4's aren't very hot, mine's running at 35-40C
under heavy load, but the G3s are even cooler..