I'm Nitrox certified and have never used it. On Bonaire I could have all the free Nitrox I want. No thanks. Why? It's a PITA. 1st you have to calibrate the analizer, then test the tank, then log it in. 2nd you have to not only monitor N but also O2 (over multiple dives) and watch MOD.
I just want to grab my tanks and jump in the water. I've never had a problem with SI, NDL, etc. doing 5 dives a day. Nitrox - no thanks.
If I want to look at rusted crap I can drive over to the local junk yard. Absolutely no interest in wrecks.