Interesting, @jet2359, I agree with most of what you said. I came into this from "the other side"; was big on high end, speaker based audio for many years before getting into headphones. Went to the shows, stereo shops, belonged to clubs, started with entry level high end and got a pretty high end set up (Linn Turntable, Krell Electronics, Thiel speakers). Speakers have an intrinsic advantage over headphones, that is space. There are only a few basic technologies, cone, electrostatic, magnetic planar), but you have much more room to design the enclosure, materials to play with, ways to connect things up. IEM's are starting to explore things like electrostatic and magnetic planar, maybe that will take things further (waiting on an iSine20, liked them at last year's CanJam NY, but really hard to listen to open headphones at a show), but there is really limited space to play with when something has to fit into your ear, and the 2 basic technologies, BA and DD, can be tweaked, but still have their characteristics that are limiting to some degree. Over ear headphones are somewhere in the middle-there is a bit more real estate to play with, that can help with the design and variety to some extent. My experience (and I don't have as much experience with TOTL iems as the rest of you) is that over ears vary more than iems do sonically. But, in the end, there is no perfect sound-it's impossible to reach "The Absolute Sound" (what a great name for a magazine; have to start that one...)-it's not even possible to agree what that is. Is it Studio Sound? Is it the sound near the musicians, in the booth, that the spectators hear? Is it the manipulated/eq''d sound the engineer finishes with? As heard through his monitors? Can you know if you didn't make the recording? And, live, is it the sound on the stage? The sound center 5th row, or from the back? Can it be miked? And on and on.
I have a friend who recently got $20k Soundlab speakers (driven by a Krell Amp and a Yggy). He has a dedicated listening room, extensively treated for reflections, everything properly placed. It sounds great; doesn't touch a live show. And a friend of his has a system that cost more than $100K, great room for it (boy, would be nice to have this disposable income...); again, really enjoyed listening to it, but it isn't live by any shot, it's a different experience. So, it comes down not to real sound, but sound that matches your preferences in the end. My problem with speaker based stereo is the rigidity of it. You are prisoner of the room and the sweet spot. I just love laying in bed and listening, walking the dog and listening, don't love being a prisoner of the sweet spot.
TOTL inflation really hit hard in the speaker-based high end world. When I started out, the Stereophile Recommended Components list had gear that cost $3-6k; not cheap, but it was possible to get Class A for people that were obsessive but not really wealthy. Now, amps costing $50k, speakers costing $100k populate "Class A". Headphones are starting some of the same inflation that other gear went through, but the stuff we consider very expensive ($3-5k), is considered "entry level" by the high end speaker-based world (Hifiman and Senn have broken through to those rarified prices, though). So, it's still easier to try different headphone gear that it is speaker/room gear. (and to think, I got into this strictly to be able to listen to music while I mowed the lawn-Etymotic was my solution, still the best universal for noise isolation I have).
My $0.02.
