I'm still trying to understand why I might want one of these. I agree it is a cheap reliable way to tell me my approximate depth. I agree that might be helpful to hold a safety stop if my computer should fail. But I see no value to allowing me to do a repetitive dive; it does not tell me my max depth so I can't use tables to plan the next dive, and I would need a timing device in addition anyway to know my bottom time. And if I had my max depth (which I wouldn't) and my BT, the multi-level dives we do today would likely put me off the table for my current/aborted dive and unable to plan for the next one.
Other than a modern version of an obsolete device, what value does it provide?