My choice for the most durable regulator would be definitely Sherwood. For warm watter definitely the Oasis, it's the first and simplest regulator designed to reduce dry mouth and throat. The Oasis features two special second-stage moisture-retention fins to keep your mouth cool and comfortable throughout your dive.
I base this choice not only on comfort!
This regulator is really durable I use one since many years and even some years I did not service it and never had a single problem. Of course always service it!! Now that I learned how to service it and also others I realize how easy it is to service it in comparison to other regulators.
The most durable regulator ? It's possible if I see what my Sherwood had to endure in the last 3000 dives I did with it
Mako