I use the Aladin Air Nitrox (which I would love to replace with the smaller and constantly backlit model,) which has served me well for over a hundred dives. I also carry my old Oceanic Prodigy which was easy to use, and it's nice to have the backup in case of primary malfunction so you don't lose a day of diving if your primary goes south. I saw another diver have his computer go nuts in Cozumel, to where he never got it out of the deco mode and had to skip the next days diving. The next day the Prodigy earned it's spot in my pocket, watching him wave to the departing boat from the dock.