Context: Most of my audio reference is from a recording studio environment. My sound assessment is probably not relevant to the normal consumer.General:I got these refurbished. They came in like new condition and I have not experienced any problems. Before using them I installed the Sony Headphones app and updated the headphones to the latest firmware. The app works as intended.Comfort:They are the most comfortable over ear headphones I have ever worn. Have in mind that the rest of my over the ear headphones are studio headphones. I have not tried the Bose or Beats options.Sound Quality:For a consumer product the sound in excellent. They are a little bass heavy compared to my studio reference headphones but that is to be expected. Very Clear on the highs and good on the mids. With the Sony Headphones app you can use one of their EQ presets or customize it to your taste which is my preference. I would not use them for recording but they are amazing to listen to music or watching tv without disrupting other people.Noise Cancelling:The ability of these headphones to isolate you from the rest of the world is amazing. While on full noise cancellation mode you can barely hear yourself snapping your fingers right in front of your face. You can opt to allow external noise in but it is only really effective if you are listening to your source at low to moderate volume.Controls:Controls are touch sensitive on the right earphone. You have to touch and slide up to raise volume and touch and slide down to lower volume. Touch and slide forward or backward to skip forward or backwards. Double touch for pause play. You get the jist. It feels weird at first because there is no clicky mechanism but you get used to it quickly. They work with both Google Assistant or Alexa.Extras:The storage case is very sturdy and includes USB to USB-C cable for charging and 1/8 cable to connect to non bluetooth audio source like a plane screen. Includes 1/8 splitter which I guess is for when you need to share a source of audio. The headphones provides spoken feedback about powering on, off, device connections etc which is a nice touch.Battery life:I have not been able to prove for a consecutively long amount of hours but I have used for about 6 hours intermittent use without having to charge it.I would highly recommend these headphones if you can afford the 350. You may find them refurb like I did for 250. They are totally worth it.