I've bought from superhappyfun and haven't been disappointed. And these guys are closely associated with it. In fact, superhappyfun will be taking the japanese releases off it's site because the ones on japanesewave are better. Now, the question is whether you are expecting a Criterion quality DVD. You'll be disappointed then. But their rating system is pretty transparent. When I bought Rivette's "Paris Belongs To Us", I knew it wouldn't be the best print, given that it was rated 6. Having to choose between a personal copy (so that I can watch this favourite whenever I like), and being denied that opportunity till somebody decides to release it years later, I went for the former. Some of the stuff was very good though, like "The Cremator" and "Hamlet Goes Business". I'll risk it with the japanesenewwave guys too, because I desperately want the Oshimas.
And, I'll get the Imamuras as soon as they are on offer
p.s. wpqx, I'll suggest getting onto their mailing lists. With superhappyfun, you have the additional advantage of accessing their password protected offers (that's where a 4-disc set of "Satantango" is hidden away). Also, I've always got prompt replies to any enquiries I've made so far, including queries about quality.