Sure. First thing I'll say is timbre is the most important thing to me when it comes to any headphone, being that I love live music and I was a percussionist. So things like decay and realism matter a lot to me especially ever since owning the IEM the Panasonic RP-HJE900. From then on I was looking for that kind of timbre in a headphone.
Since then, it's been really hard to find but the closet I had come to that kind of timbre was my modded T50RP. Over the last several months I've owned several new portables including the Momentum, MDR-1R and Amperior (since the majority of my music-listening is done on the go). All of them have been sold. When I got the 500 before those however, I knew instantly they were keepers - I could never say that about any headphone before though. And the 500 is the most expensive portable I've gotten to date- usually the more expensive the headphone is the more critical I am of them because I really can't afford to keep more of the expensive ones if I don't feel they are up to par with my preferences.
Going back to the 500, I will just say that not only do they reproduce instruments amazingly well, the layering, soundstage, imaging - the total package is just exceptional. They have a very prominent low end but the bass never intrudes upon the mids. I would say the bass is more impactful than the Momentum and 1R while the extension is great. I would say my DT1350 extends a bit lower though. Some people who prefer something more neutral may not be a fan but it's definitely controlled and tighter than the M-100 and UE6000, both of which I have auditioned. The mids are front and center without being too forward. Honestly the mids are gorgeous. Piano, vocals and strings sound very natural. You can really hear the detailed and the instruments all around you. Separation and layering are top notch and I feel it's very comparable to open cans, or close detailed monitors such as the KRK KNS-8400s, SRH-940s, and Z1000s. And as for the highs - again the most natural and refined I have heard. Very extended and very detailed without harshness. Cymbals shimmer without being overly emphasized (like the M50 for example - those have a big emphasis and make the headphone sound a bit slow/sloppy). Some headphones also can be overly bright and peaky (HD25/Amperior). Some can be uneven or even a bit too laidback to sound natural (M-80 is too smooth up top, so is the UE6000 and Momentum although the Momenum does a better job than the M-80, the 1R was a bit uneven in the treble).
Of all the headphones I have heard and owned, this is the one that handles everything wih so much finesse that I was shocked when I first heard them. My only issue with them again is that they are a bit big and bulky and despite them looking and feeling more elegant than a pair of Beats, I still could care less for the style. However those are small caveats. They are detailed and MUSICAL. I think that's the best way to describe them.
Anyway, don't take my word for it this is all subjective. Of the many headphones I've had in the past sonically, either one spectrum or the other was lacking or perhaps it was too congested-sounding, or perhaps it was too colored for my taste. I feel like these are amazing all-rounders from classical to rock to EDM - you name it. I just want to encourage people not to judge a book by its cover and really try them out if they can and come up with their own conclusions. I paid $322 for mine and feel they are worth every penny. I haven't felt that way about any other headphone I've owned (unless they were budget cans) except for my HJE900. If you can get these at $300 that's a great deal. $200 would be an absolute steal.