I called the LBS and they recommended Conti Gatorbacks. the guy said they were more durable than the ultra race tires I had, but he said they are heavier. asming I want something that is lighter/faster - should I avoid a tire like this or would I never notice the difference?

I don't mind spending a few extra bucks to get a better tire that is lighter/faster...
GP4000s II sounds like a good one...