I have been using for 8 years plus and I love Geezer gas! At recreational limits MOD O2 up to 1.6 is less narcotic that Nitrogen! Deeper maybe, but thats why you switch to Tri-Mix. For five dives a day and Cave diving you can't beat it! I will tell you this Cal-Osha has their head up their ass when it comes to Public Safety diving and Nitrox! In our county you can't get below 100ft yet if you use 32 or 36 or any mix greater than 21% you have to have a Deco Chamber on site! It is like living in a bureaucratic stone age. Divers would be safer and have bigger margins and we have seen a state ranger bent on Air in a search that wouldn't have been a problem on Nitrox! My 4 cents, inflation!