Ceric, Super Potato is SUPER cramped. That's my only complaint about the store. A lot of shops in Tokyo have no choice, though. I've read that they recently opened up a new location in Ikebukuro, and that they have several other locations in Osaka.
Johnny, I unfortunately DON'T have a 64DD, but I have four games for it (including the two I bought from the video). A few years back, they had one for sale at Super Potato for like 50,000 yen (at the time, roughly $500) that came with 5-6 games, N64 mouse, Radnet connecter and a number of other goodies. I saw it at the store for two years or so until somebody bought it. I really want to get one and try out Sim City and the F-Zero Expansion disk that I have. Freakin' awesome!
Btw, somebody once told me I looked like George Michael. I didn't know what I should think of that...