Bought the watch at the end of December 2012. It came dead on arrival, so it got sent back to Doxa for repair. It was sent back to me early February 2013 and I've been wearing it continuously since. Took it out for four dive outings with a total of 15-dives including 2-night dives.
While I like my other Doxas with the funky dive table dial, my eyes simply can't focus on the tiny markings. Yes, I do have bifocal lenses for my dive masks. No, it doesn't help. So with the sapphire bezel, it was a blessing. Highly visible in and out of the water. The glowing bezel at night is also a very nice touch!!! Though I would have preferred the bezel to glow a bit more, but it's visible enough, I suppose.
What I like the most is that the tough sapphire doesn't get a beating like the aluminum bezel. Four outings and not even a scratch on the 4000T, while the other Doxas got all dinged up. Not that I mind the watches getting scratches, I just want to comment on the durability of the sapphire bezel.
I do have a few minor complaints:
1. I wish that the cardinal markers (12, 3, 6, 9 o'clock markers) to be more distinctive. Yes, they are slightly bigger, but not at first glance, and especially not in the dark. Doesn't affect function any, but it's definitely a preference of mine.
2. The bezel wiggles a bit when compared to my 5000Ts.
3. The sliding bracelet buckle (or whatever the correct terminology is) doesn't click in and out, especially out, as smoothly and positively as the 5000Ts either.
Otherwise, I'm very happy with this watch. Doxa, please, please, please, consider making one in blue or yellow. Better yet, turquoise!!!