Just to share my views on these cans as I recently managed to purchase them on a good deal. As with most user reviews, my opinion is subjective, hence your mileage may vary.
Build quality: Pretty decent, the 1ABTs front caps are made of plastic as opposed to the others in the MDR-1A range, probably because of the touch sensor. Leather cushions are of good quality. Made in Malaysia
Fit: Fits as well as I can imagine for closed cans (I generally prefer open designs due to less constriction and larger muffs). The earmuffs while large tend to bump into my (larger) ears still. Ok for a few hours listening but then begins to cramp my ears : P
Controls: Only one power button. Touch controls take a while to get used to but work ok. Still prefer physical buttons though
Ability to be wired: Good move by Sony, as it extends the flexibility and longevity of the cans
Battery Life: So far very good, not worried about having to charge this every day
Very general impressions of the sound (via Apt-X and and various file quality levels from AAC/MP3 to ALAC) - For reference, I am familiar with the performance of headphones/earphones such as SR60, HD 580 & HD 598, and the Sony SBH-80
- These cans have a pretty decent soundstage for a closed design and are generally very musical and enjoyable with most genres. There is a lot of bass and mid range control probably due to the driver design and complements bass runs and helps give a better sense of the artiste's vocals textures
- Genres like soundtracks/Jazz/Vocals/Ambient-dance/Well-produced pop/rock pair well. Busy rock/dance tracks and overcooked recordings much less as the sound gets fairly 'congested' (Just speculating, could be due to the codec not being able to keep up, and also the closed design)
- A lot of detail can be heard from good recordings (double edged sword with bad recordings)
- Very forgiving with lossy files AAC/MP3 in general
- Overall a sense that 1ABT's full potential is held back by the lower quality codec. Will need to verify with the wired connection/LDAC
Overall, based on my initial listening impressions, these cans seem to come close to the HD598 in terms of overall enjoyment (though I still prefer the HD598 overall - but it isn't wireless to be fair). I rate the 598 very highly in terms of price/performance, and given my impressions are from wireless connections, and not the optimal wired/LDAC input, am overall impressed with the 1ABT.
Am now very curious about LDAC, perhaps will wait for a sale to pick up the A-20 walkman
P.s - Streaming via Bluetooth AAC codec on iPhone is acceptable, and definitely better than via SBC, and I was surprised that the general musical enjoyment is still there, likely due to the good design of these cans. However, there is more pronounced sibilance (to me) on more tracks.