My gripes with them are the obscene postage charge they don't tell you about till you get to the checkout even on a load of tiny items.
Secondly some of the items they say they have, you pay, they contact you saying some of your parts are actually out of stock and will have to come from japan.
I don't use them anymore, I go to the yamaha dealer instead, he's the same price if not cheaper, no p&p,
Also better advise so you don't order the wrong stuff which luckily I haven't done from suttons.
Last order I made from AJ Sutton was for the airbox snorkel pipe - paid up front then a few days later got an email saying "It's a specialist part that comes from Japan..." (a piece of molded rubber...)
Literally, and I'm not joking, 4 months it took for the snorkel to arrive!
But saying that for the odd bits like the clutch push rod & bearing & suspension collars that you wouldn't get anywhere else. The rest of the stuff I go to Bill Thomas and he orders it from Yammy himself.