I've ordered from Paper Moon before.
I think I chose them because it made the most sense.
Their shipping is high, but their prices on the stuff is the best I found. The shipping being more makes sense, since it's been shipped from his location across the ocean, but the way many stores mark up the price of the japanese stuff just because they can isn't acceptable in my eyes.
It's a teeter-totter, almost. Some charge little shipping but large increases in the cost of the items. Others charge relatively cheap prices for the items but higher shipping. I just feel like the latter is the better way to go.
Back when TPCi allowed japanese cards, 100% japanese decks, I ordered multiple boxes of a few DP sets with no problem from Paper Moon, and I think I've gotten all of my japanese deck boxes from him.