I've used these tires for several years - everyday cycling, training, touring, and triathlons. No issues whatsoever. Stand up to every day use and have not had a flat in years. Grip is above average, lightweight and you can't beat the price from WBW.
The Continental GP 4000 S II 700C Road Tire is the best road tire available. It has superb grip, rolling resistance, and puncture resistance. It is also very light. It does everything great and does not sacrifice one attribute (grip, weight, etc.) for another.
Well, out comes the GP 5000 for 2019, but I still look to the 400 for proven performance. You can't beat this tire reliability, grip, strength,....it has it all. I'll tell you how it lasts when I reach the 10,000 mile mark!
I purchased these tires ignoring the flat tire reviews over the superior performance reviews. No doubt, these are fast tires but with a HIGH cost - FLAT TIRES! 200 miles 4 flats. I inserted liners - still flat tires. I ride on chip seal roads - never had a problem until now. Going back to Gatorskins!
I used to ride exclusively on another brand of tire. A riding buddy said I should consider Continentals. The pair I ordered from Western are my reserve tires. The first set I bought ARE STILL GOING STRONG....5000kilometers ( about 3000 miles) ....NO FLATS !!!
I ride 250 - 300km a week on roads. I spent more time repairing flats than I did riding. Took the tires off after approx. 2 months of use. I was getting flats weekly (sometimes daily). Only once did I find a reason for the puncture (staple). I replaced them with Gatorskins and haven't had an issue with around 2000 km. on them.
I needed new tires and went the Gatorskin route bec I did not want to worry about flats. They were fine but I could tell how much slower I was. I am training for Ironman NC. So I had long 100 mile plus rides where I was just slow. I had a friend tell me about these tires and I saw they were on sale so I bought them on this site on deal. Best decision I ever made. They are fast! Same route-40 miles, same weather conditions, same time of day and I was 2 mph faster on these tires. Love these tires.