Comparing this headphone to Philips Fidelio X2HR and Beyerdynamic DT770 PRO.
First impression is that it's a stellar craftmanship, feels high quality and is a step up from the DT770 PRO in terms of build quality.
One thing I absolutely HATED with DT770 PRO was the cord, it's stiff and non-compliant (and too long). The cord(s) coming with DT700 PRO X is much much better, it's fairly soft and very compliant, it also transfers less sound from the cord into the ear cups.
The foam in the ear pads feels more comfortable than DT770 PRO.
I've been wearing the headphones for about an hour now and they still feel comfortable on my head. I use glasses as well and it doesn't feel like the headphones are trying to crush my head.
It feels like the DT700 PRO X has a tiny bit more sound leaking out/in than the DT770 PRO's.
Now when it comes to the actual sound it's a bit of a disappointment for me. I only use headphones for the enjoyment of music and such, I've been very happy with the sound of the DT770 PRO and of course X2HR.
First impression with the sound was that it's very harsh, a lot of treble with very neutral bass. It doesn't sound at all like the DT770 PRO, not even similar. You shouldn't see this headphone as an upgrade to DT770 PRO more than it's visual appearance.
Music that I'm able to enjoy with X2HR are not enjoyable with DT700 PRO X in a lot of cases. It requires a good quality source or it will really reveal how bad the sound is from the source.
I bought these headphones in hope of an upgraded DT770 PRO-experience but it's simply not. The price is not justified if you're going to use these just for enjoying music, buy the DT770 PRO's and modify it with a detachable cable if you can.
Update after three months of daily use:
This is now my daily driver. I never use my X2HR anymore.
The headphones require some burn in for sure, in the beginning the sound was almost terrible (the treble) but now the sound profile has softened a bit and is very pleasant. Bass is spot on and not overpowering, bad quality sources are terrible to listen to with these headphones as they are very detailed. The only negatives I have to comment about these headphones now are that they become uncomfortable after several hours of use (pressure on the ears, I use glasses so I'm prone to ear fatigue when using headphones.) and the high price.