I soured on Challenge clinchers after shelling out real money, then finding them extremely hard to sit evenly on Open Pro and Velocity Aero rims. Blew one off and destroyed a tube (aftrer spending more time than I ever have trying to mount it absolutely evenly. Decided after that I could never trust them on a fast descent down roads I didn't know. Went back to the lesser but far less exciting (less exciting in a totally good way!) Vittoria tires, Been using Vittoria Corsa G+ and G2.0 the last three years and love them, Completely traditional thread' the ribbed thread so many training cotton sewups had 45 years ago. Got reminded why I like that tread so much. It is the best for climbing back onto the road pavement and climbing out of ruts and cracks. In other words, sparing me of crashes.
A story to that point: My first year on those tires, riding a two lane country road, Car speed 50 or more. Line of cars coming toward me, Last car, a hot Camaro or something, pulls out and passes. At that moment I came to a dirt farm road on my right. Pavement widened 2' at the farm road. Moved over. Camaro went by, then "oh s***! I'm headed for the ditch paralleling the road!" At the end of the pavement, now a few feet away was a pile of gravel. Well, no choice. I gotta get back on the road or at least try. So I cut hard at the gravel, Bike simple turned onto the pavement; no big deal. "Whew1 That was excessively interesting!" And I've been sold on those tires since.
I've ridden a few of those tires to nearly through the tread. They do start getting too many flats at that point but it takes real mileage to get there. Closest ride I've seen to really good sewups on a tire I trust completely.
Ben