I recently bought a pair of DT700 Pro X thinking they would be a substantial improvement over my 2008 ATH-M40fs but I was kind of disappointed. They sound like crap to my ears without EQ (boomy, underwater, muffled). Then I came back to my old pair, also thought they sounded like crap without EQ (harsh, absent bass). I took the time to EQ the DT 700, then took some more time to EQ again the M40fs, and the DT 700 is not much of an improvement, not for the price paid. They sound decently good with an EQ, have a little bit better imaging, separation, soundstage, comfort etc. but I expected better stock sound for the price.
Maybe my expectations are unrealistic and I should up my budget a bit and get closer to real hifi instead of staying in the mid-fi class?
I tried a few headphones available at my local store and the DT 700 Pro X (also the DT770) were the most comfortable of all. I bought the DT 700 Pro X because of comfort to wear them for extended period of time throughout the work day. They can be a little too tight maybe, but they don't really hurt my ears. I expect them to loosen over time.