Nope - heard good things about them certainly (depending on the make and model, some models had well known issues from what I have been reading) I have a few friends with japanese scooters as well which have been ultra solid machines for them - but as you mentioned, different beast in terms of reliability (all mopeds are going to break if you ride them - sooner or later. Cheaper construction than most scooters. :)
For personal experience however I just have ridden the Tomos, Puch, and Jawa brands - all of which I've found to be good for mopeds. (The tomos, despite the wiring issue has never failed to start and never failed to move... the only thing the wiring problem affected was the headlight went out on me - and considering I use it to get up to work which is 42km away reliability is a fairly major thing for me :)
Besides the wiring fault could be partially due to being overstressed - I've gone down on the bike twice (in both cases car drivers did rather illegal things and basically gave me a choice of eating pavement or eating fender... I choose pavement, it was moving a bit more slowly) Still, after sliding around for a fair distance at 30kph, the bike still ran fine - only some plastic body bits cracked and scratched, mechanically it was still working just fine.
Still, if I ever get a chance to buy one I can afford (since I don't actually NEED it I'll admit) I'd love to add a japanese moped to the collection and give it a try. But I'm happy enough with the Tomos as my daily ride. :)