I only have two Quadra PDS PPC601 cards, one 100MHz and the other (I think) 66MHz. I can't remember having any problems with them, across all the Quadras I've used them in, which includes a 700 and 950. Two successes may not be much to go on, but that's all the experience I have to give.

The room they've been used in hasn't been a particularly well cooled one either.

Dana