I also am not real big on fishing deep with a fly rod. If i'm going to be fishing mostly over 5' deep, out comes the Quantum.
I think the "extreme nymphing" technique would be a useful technique for that one huge deep pool on a river where other techniques work the rest of the time. I'm one of those weirdos who keeps a spare spool with shooting line with me for nymphing and i think it would work for that.
For anybody that has ever wanted a setup like that, thefullcreel.com has a 333 shooting line for cheap. With that and an Echo reel, you would have a set-up that is extremely popular and productive in Europe. If you leave the backing at 100yds or so, you'd have room for shooting heads too!