There have been fast 6.5's since Winchester introduced the 264 WM back in 1958 and none have ever caught on. The PRC is most likely the best one yet, but it is still struggling. It is a good round, but lots of good rounds never catch on in such a crowded field.
When I look at the 6.5PRC there are 2 things that prevent me from buying one. The 264 WM earned a reputation for burning out barrels with less than 1000 rounds, the PRC will be as bad or worse. And while it shoots flatter, and farther than a 6.5 CM, my 308 and 6.5CM are already capable farther than I can shoot. I couldn't use it's advantages. I think others are concluding the same.