Solved my problem with my flats on commutes! After 2 flats in 8 years using Gatorskins (even ran on rear tire through to the cords), I had forgotten how important it was to have a tough tire for commuting! I got a new bike last year, flatted twice on the Schwalbe tires that came with the bike, so I changed to Conti GP -Season (great handling tire) but flatted 5 times in 8 weeks!! (lots of tough paths, sidewalks, etc.) - so I wanted Gatorskins, but decided to go to the new, even tougher Gator Hardshell tires - 12 weeks later no flats, no worries - perfect for my commute! A little difficult to install compared to other Conti tires, but well worth the effort. Highly recommended for commuting, tandem, and any application where durability is paramount.
Used this past summer on Pittsburg to DC ride on GAP and C&O trail. 5 days with 2 days of rain. Tire performed better then I had hoped. Zero flats in 400 miles of fully packed trail riding. I will buy this tire again
Ride about 2,000 miles per year and have used the GP 4-season for 15 years or so. I have had very few flats, probably less than one per year on average. Great traction and handling. Hard to beat this tire at the sale price.