I think a lot of us here are making too many broad statements and judgements... As they say, "horses for courses."
It would be better to say "overrated in aspect X."
Example- for people who desire sound staging and detail, who have cash, the HD800 is a steal- to get that last few percent, we are talking Stax Omega prices.
Take the HE-500. People praise its detail retrieval- that aspect is way overrated. It is outperformed by headphones half its price. Its Fun Factor is quite underrated, though.
The difference with Grados and the LCD2s, is that nobody recommends them for people looking for neutrality. In this respect, they are NOT overrated, as nobody claims that they are good at a feature that they lack. Though, the LCD2's near cult following is a bit irritating, I will admit, However, I highly doubt that it isn't at least in large part, justified.
To truly earn the moniker of completely being overrated, sound, features, and aesthetics, you'd have to go as low as Beats, Bieber, and Triports. Arguably, also, the Abyss is, whose being priced as much as a a Stax 009, is unforgivable, and clearly its price was determined before they figured out how well it worked. That sales tactic of making it seem better than it really is due to artifically inflating its price (hello Kirby Vaccuum and Louis Vuitton, I'm talking to you!) does really annoy me.
Example of not overrated- wow, those Skullcandy or V-Modas, as a fashion statement, run the risk of being underrated, at least here on head-fi. They look awesome for their target demographic, and that's what they are for.
The M50's... My sister is very picky. She wants a durable, transportable (goodbye ATH-A700/900!) circumaural headphone that offers some isolation (that narrows things down a lot), fits people with small heads (goodbye K550!), has a flat [Clarification: I really should have said a not-recessed treble]frequency response (goodbye Shure 840!), is drivable without an external amp (goodbye DT770!), is neutral and not dark sounding (goodbye HD380!), isnt flashy (goodbye V-Moda!), isn't Sony (bad experience in the past), and is a firm max of 200 USD new with warranty from a place with a good return policy.
The M50, frankly, is by far the best fit, and to her, not at all overrated. See what I mean?
Now, maybe the most egregiosly underrated in pretty much every respect are the lower priced Koss or Monoprice offerings.
