When I clicked on his link, the belts pictured are from "Bando" not Mitsuboshi, so I don't know where you are coming from. I'd have no issue with Mitsuboshi belts myself, but Bando....that's asking for Failo.
***Edit**** The timing belt is Mitsuboshi....I see. Still, you'd have to be a moron to use it when you can get a Gates belt for probably the same price.
Ya'll are free to buy where and what you want, but I'm SOLD on Gates when it comes to belts. I'd also use an OEM water pump from Subaru all day long over a pot metal replacement from China. Once again...your call.