My experience with maperformance wasn't outstanding, but it wasn't horrible. I got a receipt for my order placement a WEEK after i placed it. I expected to have my product by the time i had gotten this receipt saying they'd finally processed my order. I was also pretty bent when i was given a tracking number for pistons and main studs, and i received a box containing only main studs. The pistons finally showed up a week later (well over 2 weeks after order placement) after i bitched about things taking so long. The guy i was in correspondence with was fairly understanding, took responsibility for processing my order so slowly, and apologized for the tracking/shipping issues. He also offered to discount my next order as a token of apology. Good business decision.
This is a hell of a lot more than i ever got from another company out of PA which i won't be mentioning the name of. I may actually deal with maperformance again. Like i said, my dealings with them weren't horrible, but the entire transaction wasn't nearly as smooth as ordering from FP or JayRacing. I've actually seriously been considering getting those mounts from them. I've not heard of others having problems with the company at all so i suppose the delays i experienced are not a common occurrence. At least my parts didn't show up broken like they did from another (very well known) company i will no longer deal with.