The 42-20 and 51-30 use japanese quartz movements and are built to withstand abuse with a hefty cases and screwed on bracelets. IMO these are the only 2 models they make that are worth a look. Every other one I've taken a good look at his some chintzy things going on with the materials or assembly.
I have an all steel 42-20 chrono. Its very durable and comfortable. Smooth flat caseback and very short lugs, sits on the wrist nicely for its weight.