I go deep, cuz thats where the pretty fish are im trying to catch
Its one of those conditioning things....after a few hundred dives, you get conditioned to it.
Early on, i'd blow thru my tank in 25 minutes going deep.
Now I can go to 130 on a 28 blend nitrox, hang out for 12-15 minutes, work my way up and still get 60 minutes on the dive...this takes time and many many dives to get to this point.
Yes, i agree deeper isnt always better.