I used to own the Charles Darwin Edition myself, and while I never had the strap detach on me, I was often nervous. What I never could figure out is why IWC implemented the quick-change strap on the Aquatimer to begin with, since to my knowledge. they've never offered an alternative OEM option. I tried the Charles Darwin on a NATO strap a couple of times, but the design and placement of the bars/lugs made the watch look awkward on the NATO. My main beef with the Charles Darwin Edition, and the reason that I ultimately gave it up, was that I found the chronograph seconds almost impossible to read against the dial. (A major design flaw, in my estimation. 🤨)
I occasionally miss my Aquatimer as a knockabout/beater watch, but not enough that I regret trading it away.