I normally wore out my tennis shoe in 3 months. Because Prince Cobra NFS shoe has a 6 month warranty, I bought a pair about 1 or 2 month ago. After wear it for two weeks playing, I have feet pain I never had in my life. I can feel it when I wear the shoe walking. If I walk in house bare feet, I will feel it in first few steps. It is not kind of pain you feel in muscle. It is kind of pain in the bone structure. So I stopped wear this shoe playing tennis. Once I switch back to my old HEAD tennis shoe, I feel no pain in another two weeks. I will strongly suggest to stay away from prince shoe, especially the one with 6 Month Durability Guarantee. You will never get a chance to wear them out because you cannot wear them to play tennis. Any comments? BTW, I already contacted prince twice through emails and not getting any feedback from them yet (two weeks already).