Agreed. The MDR-7506 is a "studio standard" for reference/monitor headphones in pro audio and video. The frequency response is not "enhanced" at the low end like the Beats and many other modern headphones. I don't think the curve is really flat- they always sound a little bright to me (thought in that hear-more-detail sort of naturally pleasant way), but they're definitely more flat than the Beats. The 7506 is like $90. The V6 has the same drivers, but doesn't have a gold plated plug (seriously). I got my V6s refurbed for $50. The closed earpads passively block external sound pretty well, and they're relatively comfortable. They don't come in green or pink, but they sound good, are still made with some metal parts for durability, and they're way cheaper than Beats. Source: work in a couple different TV production studios, a friend that's in the audio/acoustics industry, and a lot of reviews at B & H.

Those are great for tracking and/or studio-critical ( read: intense, "What was that??") listening but they're pretty shrill for general listening.

I find them fatiguing.

I cannot get past the Koss KTXPRO-1. They're very inexpensive, but I can mix on them, they're comfortable and priced very well. There's no fatigue with them.

I really do throw a rough up first on the 'phones because it seems to get me to a decent first mix fast.

I need to buy a nice pair of Grado and/or Stax just to try to wean myself off these things. :) Don't mean to sound fanboiish, but I've used 'em now for going on fifteen years. Headphones are like that.