I've always been fascinated by these two (mostly) Japan-only computers. Of course Konami got it's major breaks in Japan on the MSX and the X68000 is said to have some great arcade ports. Still - other than emulating to try them out (which always feels flat compared to the real thing) what are some other collector's/gamer's opinions on these two machines?

Also - are there more interesting Japan-only computer machines I'm missing?