Just wanted to share my experience and impressions after purchasing a pair of these to test out based on all the good things I heard, going in blind so as not to taint my experience.
My first impression was being blown away by the design of the unit and comfort - total class act as to be expected from Sony. I have been using HD800 S exclusively for the past several years and have found them very light and comfortable and can wear them for hours on end, but I never expected the Z1R to exceed them given their size. It was like wearing a pillow on my head. Perfectly balanced, no pain from clamping pressure on my ears or on top from the headband.
Second impression was how meager the included cable was - for the money I think Sony could do much better on this given the premium materials used everywhere else. Take the money away from the leather box which I'll never see again and put it towards a nicer cable.
Third impression was that the mids were quite recessed which was a pretty big turnoff coming from the 800 S. They felt veiled and quiet, which was in sharp contrast with how wide and luxurious the rest of the soundstage was.
I thought that the mids alone would be a disqualifier.. however I was shocked by how much my impression changed over the next 30 days. I grew to REALLY like these headphones. If I had to use one word, it would be 'engaging' - everything I listen to sounded effortless, and putting them on my head every time was a pleasure. The isolation afforded by the big ear cups, big pillowy ear pads and closed back design was really novel after having open backs for so long sharing a home office with my wife.
After a while, the recessed mids didn't really bother me much at all. And the low end was so luxurious that it more than made up for it. Not in an excessive way - I was expecting a bass monster.. I felt like they were exactly what I wanted from a headphone.
I returned them as I was having a bit of trouble justifying the price tag and wanted to try a few others before settling on a new pair, however I keep finding myself thinking about them. I have a pair of LCD XC on the way to demo, though I am a bit worried about the weight and clamping pressure. I forsee repurchasing the Z1R in my future..!