Clock speed doesn't really matter that much. GO FOR CHACHE! The more you have the better. That's why the q9550 is still so beast!
what the heck are you on about? are you telling him to go buy a q9550 for $300???? go troll somewhere else, intels 2500k has less cache than the q9550 and stomps it into the ground. Lots of cache doesn't make a fast cpu, but it often helps. the 955 performs similarly to the q9550 which is really not an option anymore.