As framiga said, mysticview as a viewer. It's excellent.
From my personal experience with my cv64 card, cgx is the best choice regarding speed. I'm running P96 now, though, after having tried to make cgx work properly for about a day last time I reinstalled.
Whatever P96-lovers tell you, once you've had your superlayers, being without them just feels...empty (oh, and slow

.
Sincerely,
-Kenneth Straarup.