Surprisingly, I don't think anyone here has installed aftermarket rearsets yet, at least I can't find any mention about it. You may be the first one here to do it and there doesn't seem to be a lot of Z650 sets out there.
Bought RSV ones they look good. It took about a month to get to me. So in that respect customer service is about what you would expect when you buy online from Thailand. But it was $257 versus paying 500+ for the Italian ones.