I keep hearing about fatigue after diving and makes me wonder about what are you people doing on your dives.
I come back to the surface hungry sometimes, specially if I saw scorpionfish, lobster, grouper or other delicious stuff. Other times I come up buzzing with excitement because I saw something very cool. But even a so-so dive recharges me, I get fatigue with the nonsense I have to deal with topside until the next dive.... fatigue diving? nope. Doesn't matter if diving air or nitrox.
I like nitrox for multi-dive days. My regular weekends are just one dive on Saturday another Sunday (as long as the seas are not too rough) for that one dive a day I think nitrox is a waste. 60 feet for 60 minutes is a good rule of thumb for me. If a whale shark comes by late in the dive, I'll push the envelope and live with the consequences.
Now for lobster min-season or any other multi-dive day events I'll dive nitrox for the benefits of longer NDL's .