Well, I got my license in 1983, 2600 hrs in Robinson and I paid for everyone of them, bought and used and sold 16 r22 and mainly r44 machines, never had an issue, I have always run them hard and fast, but not in mountains. I can see where you could have problems but not in my experience. Flown as dictated by Robinson I think your safe, but I wouldn't buy one to fly around New Zealand or similar mountains. Taking in to account all of what has been said would I fly / buy another? Well yes but I am not real keen on the 22 anymore but happy with the R44.