I've been riding all year on a set of Michelin Orium's. They were on the bike when I bought it. At about 1100 miles I got two flats in a week. The back tire had a couple of small cuts, the front was fine. I always pump them to pressure before each ride.
I bought a pair of Conti GP 4000's and rode them 20 miles today. Wow what a difference. immediately felt less rolling resistance and just seemed faster. Now the Orium's are not top of the line but mid-grade. At the end of the ride I was .9 mph faster than normal and they just seemed to be more comfortable on the road.
Can it be the tires or is much of this in my head?