I appreciate the well considered advice regarding headphones and I do use them occasionally but only to shut out competing activities in our house and to limit my intrusion on others. Even though their sound reproduction is incredibly resolved, it just doesn't sound natural to me as if, like Larryi stated, the sound is originating in my head with no sense of a soundstage. Whatever the reason, even if only psychological, for everyday listening I'll not be using them.
On the other hand, because my stated goal is to acheive better detail at lower volume settings and, as I am very satisfied with my system at moderate to higher volumes, and because chasing it in other ways would be more involved and expensive, it probably makes better sense to develop a bit more flexibility and continue to use them for those described ocassional circumstances.
I've needed to upgrade my headphones anyway so will look into that. I have the Bose noise cancellers which work well for their designed purpose but are not well suited, IMO, for anything like audiophile listening. I also have a set of "fairly" decent on-ear phones that sound OK but don't do a great job of shutting out unwanted environmental sounds.
I have a question, though, regarding length of headphone wire. Although my seating position is only about 14 feet from my amp, the length of wire necessay to reach my location w/o running it across the living room would be about 28 feet. Will this be an issue?