I had 2-3 Marinemastets in the past, but none was able to stick for long. This one I will keep forever. You are right, the monocoque case design is one of the highlights, but also the hi-beat movement, great dial design with minimal text and virtually all...
It ended up being a bit too big and heavy so I resold it. Had it been in titanium, I would have kept it as I agree with you: one of the best divers ever made, Seiko or other.