My headphone experience is pretty simple. I've only owned one set of decent headphones. Massdrop/Sennheiser HD 58X Jubilee. They are the first set of open back headphones I have ever owned.
I never heard about Massdrop until started researching on PW which headphones might go good with the binaural samples on my N1X. Prior to the HD 58X Jubilee, I owned a pair of Shure 440 that someone gave to me and they hurt my head when I used them for any protracted period of time.
Here is my comparison between the two.
1. Fit and finish.
They are lighter and more comfortable than the 440's. I could wear them for hours if I needed to. They are also very quiet compared to the 440's that rattle and make a lot of noise when handling.
2. Musical Sound quality.
There is more clarity and instrumental separation with the 58X's. Also, they sounded better as the volume was increased compared to the 440's that seem to wash out more as the volume went up. I was able to drive the 58X's with both my iPhone and MacBook Air to ear damage decibels if I wanted.
3. Piano Sound quality.
It's easy to preform a comparative analysis with the N1X since it has two headphone jacks. I first listened to the demo songs on the the N1X and it was readily apparent that the 58X's had a more pronounced bass and evenness across the frequency spectrum. The 440's sounded a bit hollow/shallow with less frequency separation. After a while of playing the piano with both I stopped reaching for the 440's
I paid $160 for them and ended up buying a pair for my wife as a birthday gift. She loves hers as well.
Have a look.