The Zipp Tangente Course Clincher has been my go to training tire for the past 2 years. Like any tire it will flat out with steel splinters from blown car tires and sharp fragments. However, I never have to worry about side wall blow outs that seem to be a common event on Continental GP 4000S. I have had my share of sidewall blowouts leaving me stranded on hot Arizona roads with no cell phone reception.
I have put deep trust in these tires and change them out every 3500 miles of riding regardless of remaining tread life. I ride 300 miles per week on average according to Strava.
This tire is light durable and rolls very well. At this point there is no reason to change training tires.