Some people say Ultra Sports last for over a thousand miles without any flats, while some reviews say they're very prone to puncturing. I mainly commute around suburban/city areas in dry weather, and I'm currently using cheap Kenda K35. I've yet to get a flat on the K35, but I was wondering how the Ultra Sports would compare?

Edit: Thanks for the responses! It seems the Ultra Sports are decent but not great. What 27" tires are the best bang for the buck, again, mostly for commute?