Like the OP, I had no prior experience with which to compare the stock (Specialized Pro II, 25cm) tires that came with my bike. I got 4700 miles from my front and 2400/2300 miles from two rears. I had no flats or other issues running at 110 psi. I started riding this summer at 210 lbs. and eventually dropped ten pounds. I just replaced those tires with 23 cm Vittoria Rubino Pro Slicks. After only 200 miles I cannot assess their durability, but the ride improvement is significant. Rolling resistance is noticeably reduced. I'm climbing in higher gears and my speed has increased about 3 mph for the same pedal effort. Of course, the slicks are dry tires, so I'll need caution in cornering in the wet. I try not to ride in the ride and the tires seem a very big improvement.