That's fair; I actually haven't used Nitrox since I got certified (I did use it for one dive as part of the course), though I plan to use it on an upcoming LOB trip. I don't think everyone needs to use it on every dive, for the reasons you stated, and some shops are probably guilty of at least insinuating otherwise to sell courses (or just the gas.) But I do think it has its place, and I thought the course did a good job of covering what you need to know to use it, at a reasonable price. (Side note: I don't think I paid anywhere near $400 though--maybe a quarter of that? I was swiping my credit card so much that trip it's all a little blurry...)
But my real question is, do you think your original instruction taught you more than the AOW course teaches today, or was the course just useless to you because of all you've learned in the 50 years since you got certified?
But my real question is, do you think your original instruction taught you more than the AOW course teaches today, or was the course just useless to you because of all you've learned in the 50 years since you got certified?