I used them back when I did my turbo build. Ordered a turbo smart e-boost 2 and the up down button function would not work, had to have one for a up coming Saturday race, called and talked to the owner and he said he was a racer and understood, he sent me a new one out that day and trusted me to send the disfunctioning one back to him, it's been a while but I think those things are around $500 bucks, most business owners would want the bad one in hand before sending a new one out to me. He even called the following week and made sure the new controller functioned properly and asked how the race went.