I was reading the positive reviews and decided to give X2's a try (having an opportunity to test and return if so wanted). I had tried on a whim a friend's Philips A5 Pro (which are a well-rounded DJ-specific closed headphones built to last (aluminum and real leather), and felt Philips is definitely on to something with their new line of headphones. X1 I had never tried.
Comfort: I have a pretty small head, and immediately putting the X2's on, I could see they were slightly too large, remaining a bit loose around the head and on top of ears. The velour surface is ok, though I definitely prefer real leather (such as the A5 Pro had, or for example the Audeze LCD-X I recently tested - velour also collects dust and wears out, whereas leather just ages beautifully with you). The memory foam on the other hand does not seem to mold much (perhaps due to little loose fit you get if you have a smaller head), so the contact to the ear is not very good.
Looks and build: I like that Philips is using aluminum, rather than plastic all around. Same for using real leather instead of faux - Take note, manufacturers of higher-end plasticky headphones. X2 feels solid all around and is well built. Design is ok, but this type of headphones with hammock-style headband, especially on a smaller head, look rather amusing with the high arch on top your dome - not a problem at home, but would be hesitant to walk outside wearing something like these.
Sound: I had very high expectations for these headphones, and maybe because of that, I was quite disappointed - or, let's say, rather underwhelmed - in their performance. The fact that they are quite bright, with overpowering treble that turns lots of singers' voice unnaturally thin (sort of stamped on, with no sufficient depth), does not go well with what I want from a pair of headphones. Bass is pretty well controlled, but it is a bit exaggerated, even slightly 'boomy' at times, so someone looking for a natural bass (controlled and true, clean) will likely be disappointed. Having said that, there's no obvious distortion and X2's are capable of very high definition and clear/clean output.
Verdict: Returned the X2's back to the store after 2 weeks. Not comfortable enough (especially for a smaller head), too harsh on the treble making them sound a bit unnatural and thin, and lacking presence especially with vocals. Bass also leaves me wanting more control and clarity though they are not a bass-head's headphones either.
Tested with: iPhone 6 (from headphone output directly, and over Airplay, through Apple TV and Schiit Modi 2 and Magni 2 (Ubers) stack) and Macbook Pro (USB through the same Schiit stack)