Jumped the gun on this headset yesterday.
So here are my initial impressions.
Note: I've only tested with BT (AAC) and cable on an iPhone 6 Plus so far.
I am sure that MUCH better results could be achieved with better source/amp.
Så you may need to take my specific music observations with a grain of salt

The creak:
OK. Since this has been a major subject in this thread, let's get it out of the way from the start.
I experience none of the creak and squeak from the hinges or joints whatsoever - absolutely solid assembly.
What I do hear is a headphone somewhat prone to "Cabinet noise/microphonics" from the plastic ear cups - which seems perfectly natural to me.
Another issue that I initially mistook for the infamous "creak", was a squeaking sound that seemed to follow my every move.
Turned out to be the "leather" padding on the earcups rubbing against the stents of my glasses - feel free to laugh

Sennheiser and Bose have avoided this issue through the use of other materials on the cup.
Definitely not a big issue for me though - and seems to away when the cups "settle".
General character:
Not at all an in-your-face character. But rather a bit dialed back.
Natural, smooth, extended sound.
Reasonable detail despite rounded top.
Subjectively I might have preferred a bit more "Loudness" factor and attack for on-the-go listening.
But this is easier to obtain by EQ than toning down an overly enthusiastic headphone

Bass:
Agreed this is not at all a bass heavy headphone.
But the sonic balance seems (to me) more of a deliberate choice of "sound tuning" from Sony, rather than the drivers not being able to deliver.
When properly asked, it is definitely capable of tight, controlled bass.
Noise Cancellation:
Very good at filtering out engine noise and steady rumble from car.
Voices or soft snap of fingers go right through though.
Slight soft whoosh background noise - as opposed to rather sharp, stressful hiss from previous Parrot Zik 2.0.
Not sure if it's better than competition, but the character of the NC brings a sense of calm and ease
As good as it is with steady noise, the NC does seem to be overly eager or sensitive when compensating for sudden changes in noise - for example bumps or varying rumble.
Others have experienced this when walking or in a train with changing pressure and doors opening/closing
Music "tested":
Agnes Obel
- Smooth and calm presentation with NC allows the proper sense of ease for this song.
Dave Matthews
- A bit more sharpness to drums and crispness to acoustic guitars would have been desirable.
Deftones
- Again, a bit more attack would have been nice. But nice vivid presentation.
De-Phazz
- Bring out the smooth, warm character of this Electro-Jazz.
Jennifer Warnes
- Good imaging and great bass extension on "way down deep".
Massive Attack
- Mostly tested for the bass. Came through with flying colours.
Niels Lofgren (live)
- Good ambience and crispness to guitar her.
Tool
- Nice control and separation on the drums and bass.
Overall:
Very satisfied with the headset - although I still feel that the price is a bit high.