Although I had no aspirations to tech diving, I bought DIN regs because the argument that the design was superior to yoke was persuasive to me, and because they were not uncommon among rec-only divers in Florida. It soon became apparent to me that, except for Europe, the rec diving world is predominantly yoke. I tried a spin-on adapter of the type linked to in posts above, but I found it took up just enough extra space behind my head to be annoying--yes, the half inch or so was noticeable. Others report not being bothered by it, so take that as just one person's opinion. Sure, DIN tank valves with the removable inserts are increasingly common, but I found that the inserts in rental tanks from dive ops that don't get a lot of requests for DIN tanks were often rusted in place and difficult to impossible to remove. Sometimes the dive op would want to remove them before handing over the tank, so as not to give customers the opportunity to lose the inserts, and I got tired of being the "exception" who had to wait while everyone else got squared away until dive op personnel found a few minutes to remove the DIN insert for me. Last to board the boat. The troublemaker. Also, even if the DIN insert was not rusted in place, in a few instances I recall that the valve fitting was slightly out of round, likely due to abuse suffered as a rental tank, and while the insert could be removed, it was difficult to impossible to screw my reg into it. Yokes are much more tolerant of such abuse; you can attach a yoke reg to a somewhat banged up valve fitting and still have it work. Eventually, I removed and replaced the DIN fittings on my first stages with yokes.
Having started down the path to tech diving, I have other regs dedicated to that, and those regs are of course DIN. But for rec diving, using rented tanks, I'm sticking with yoke regs.
