Scotty Bwrote a review of Continental Grand Prix 4 Season Tire - Clincher on July 21, 2016
Familiarity: I've put it through the wringer
I have had issues with sidewall cuts/tears on the GP 4000S tires and finally got fed up with going through a tube a week. I bought the GP tires and have over 900 miles on them without any issues. None. It may be marketing but yes, these tires are not ready to roll up to the start line at your local crit, but I have no issues cornering down mountain descents at high speed, they grip well and are durable. Not a single issue despite lots of roadside debris, etc.
If you want a long wearing, highly puncture resistant tires from a great tire company, throw a pair in your cart now.