Stu is a one-man shop, and he's inundated with long questions from tire kickers. If you order a stone, he will ship it. If you email, then he will respond if he has time to.
He also has a day job (at least the last time I talked to him, he did) teaching English and his wife works, too. That's probably one of the reasons his prices are as good as they are - if he dedicated full time to the shop, I think the prices would have to go up.
I've known him since long before he started selling things, he's an honest guy. Always has been, and started his shop because he was offended with what some of the US suppliers peddle to us (if you look at woodworking catalogs, stuff is often sold for a multiple of what stu sells - 2x as much in some cases for his very expensive items, like hand made tsunesaburo planes). We're also given a dose of BS stories in some of the catalogs here in the US, talking up things that are more or less machine made in japan.
So, if you want a stone from him, buy it. I think it's a better idea to ask questions of individual items on various forums for two reasons:
* you don't have to wonder whether a vendor is being objective
* it takes a bit of the load off of vendors going through emails and gives you more data points
Stu also has an inability to help people part way. He either answers you none or gives you a voluminous long and descriptive answer.