In the mid-70's, my first R&R from a job in Indonesia was in Singapore. I went to the Rolex store and bought a Submariner watch. It has been on my wrist for almost 40 years. It has been under every ocean in the world,sometimes to a depth of 140ft, been immersed in sand and dust as fine as talcum powder, been in temps from -50 to +130, been vibrated by everything from a jackhammer to a dirt bike. It's self winding and still keeps time to about 2 min/mo. I had to take it off once for a hospital visit. She was really pissed and took about 2 weeks to re-regulate herself after I got out. I'm convinced that if we are ever separated, one or both of us will die. She clunks now when I move my arm, just like me. I paid something like $350 in Singapore back then. I can't get her serviced now for triple that, so I haven't done it.
Anyway, if this is the same movement these guys are using, I can testify that it really is the shit.
I recently found out that since my "Submariner" on the dial is written in red, she is a really special lady. Of course, I already knew that.

YB