Just bought my 12 year old his first pair of adult tennis shoes. The jump from youth to adult will make his dad's pocketbook heavier as he shears the soles of the shoes he has tried in no time playing 15 to 20 hours per week. Today he had to settle for a pair of white Propulse 4. Hopefully they will hold up, and if not, the sole warranty will kick in. Why aren't shoes tested on the hot, hard courts of Phoenix, Arizona?