"Upper-Mid Range" is a very subjective descriptor. What one person considers middle tier vs upper tier and the distinctions in-between might be totally different from another.
Assuming that our tiers are price ranges and not quality ranges (because that's where subjectivity comes into play), an early twenty something college student with $150 to spend will perceive a very different pricing hierarchy than an early-40s salaried worker who finally has $1200 to blow on cans, or a person in their late-50s who burns money instead of firewood and wants a $4000 hood ornament for their stereo. And those are just some very basic U.S. consumer "castes". What about people overseas?
We need to define our terms here or these polls are meaningless.
I just made this up off the top of my head. For example:
< US$100 = commodity trash
US$100 - 200 = entry level listening
US$200 - 400 = unitaskers that typically only do one thing amazingly well*
US$400 - 1000 = solid all-rounders, typically with one real flaw** I would call these entry-level audiophile headphones.
US$1000-2000 = mid-tier audiophile headphones present just an amazing listening experience, with the tiniest little flaws and imperfections or leanings toward specific types of music. They've maximized musicality and dealt with 95% of the various things like intermodulation distortion, phase imbalance, sound staging, frequency imbalance, transient response. There are little tiny things that can be tightened up, but if its in this price range it should be stellar.
> US$2000 = top-tier audiophile headphones. These are like the Ferraris, Lamborghinis, and McLaren supercars. Each one has a unique sound signature in its own right, possibly even quirky but they should all be phenomenal.
There are caveats to the list above which trolls will doubtless pounce on. For example, the price points might need to slide. Maybe your top tier doesn't start until $2500 or $3000. Good for you, but it doesn't invalidate the basic premise of price tiering. Debate amongst yourselves! Also, you might really want to argue about whether a given headphone deserves to be in a particular pricing tier because it's quality doesn't justify the price. That is a support for the argument for pricing tiering, not against it, because its clearly providing a comparative structure for you to think about price-to-performance ratio and thus a tool for making you a better consumer.
* Unitaksers include things like analytical headphones. For example :
(1) the AKG K553 Pro that can be endlessly EQ'd without distorting but are very granular, aren't very resolving, and aren't musical at all. You can monkey around with your EQ settings with a pair of 553s to mimic all other kinds of headphone response curves. I can make my 553s sound like Beyerdynamic T1s or K702s, even Audeze LCD-2s, to a point. However, they never really sound amazing because they don't have any euphonic distortion built into their design and material choices like the others I just mentioned. This makes them sound unmusical, a studio engineer's dream.
(2) headphones in the $200-300 range that are insanely resolving and exaggerate phase information like the AKG K702 Reference do so by sacrificing something else. In the case of the K702, it's frequency response coloration. They're perfect at revealing very high frequency distortion for spot-checking things like strident vocals and whether or not sound staging has been preserved, but the frequency response curve puts so much energy into the treble they will kill your ears if you listen to anything but classical music on them. (Listening to an orchestra on 702s produces the effect of sitting further back in a concert hall, where all the musical energy in the bass range has dissipated and you're hearing 2nd and 3rd order harmonics of the kettle drum instead of the full impact.
** For example, the Mr. Speakers Aeon is amazing at lower volume levels with content that has no lower-bass or sub-bass. Listening to classical arpeggiated stringed instruments like mandolin, guitar, et cetera? OMG these are amazing, you hear the bodies of the instruments resonating. But add any bass material below 80-100 Hz and it's just absent. If you EQ-boost it they just distort like crazy. But if you're not listening to something with a lot of bass information, they're the most insanely great closed backs you'll find. John Peel would have loved these (he seemed to hate bass).