I use O2 full time at the moment. My insurance refused to pay until I was at a consistent 85% or below. I feel it should be covered sooner as this caused a lot of trouble. My energy level is consistently higher for the most part. Before the oxygen I couldnt make it up a hefty flight of stairs and I find I can challenge myself a bit now to get moving and have some minmal exercise. When I started just at night I hated it at first but loved the difference it made. My only complaint is it dries out my nose and gives me nose bleeds that worsen as the concentration raises. As for flights I have no idea. I will be taking my first flight since oxygen next month and have been clueless as to how I can recieve permission for oxygen during the flight. Oxygen can never hurt and you may appreciate the difference it makes. Good luck!