Sennheiser HD 650

After trying multiple headsets these things are the best and there cost reflects in the price. These are slightly on the treble side so bass is a little subdued. The sound separation is incredible. To get the most out of it on a smartphone I use a LGG6 as that has a built in DACAMP which will drive these, the sound is still fair on an iPhone 8plus.
Highly recommend these.

Bought the Massdrop HD6XX version (we all know it's HD650). Waited for 2mths to get it shipped. Absolutely great value.

The Massdrop version's package is quite a basic one, not sure if you get a better one with the original ver. Build quality is good. Clamping force is a bit high for me but the ear pads are comfortable.

Using it with the Schiit Joutunheim (with DAC module, XLR port). The sound is marvelous.

Great sound stage and decent balanced sound. Competes with my AKG K7xx for my ears and only falls short a bit on comfort. Not sold on the comfort as the clamping force is a bit high, you can bend the metal headband but make sure not to crack the plastic casing. Mostly used through an LG G6 amp which is comparable to using an Fiio E10k as a DAC/Amp through my computer.

These headphones are great, I went from AKG 720s to these. I do like the soundstage on the AKGs better, but I definitely prefer the accuracy as well as the slightly better bass with these. They're fairly easy to drive and I've used the SR71 from Ray Samuels as well as the Schiit audio Fulla 2. Can't complain about them much. They don't look the best but if I wanted looks instead of sound quality I'd buy beats instead.

Luscious sound and traditional Sennheiser build quality. If you love music, try these out, but be warned, you won't want to give them back.
The sound is amazing. If you really want to listen to music and enjoy the performance of the musicians and timbre of the instruments and the beauty of the human singing voice there is little touch these little beauties.
Nothing really. They're pricey but when you look at the build quality and then listen to the brilliant sound you can understand why they cost a lot.