For the past 4 months, I’ve owned both the Bose Quiet Cofort 35 (QC 35) and Sony MDX 1000X (MDX). Both are noise canceling over the ear headphones. Both are expensive (~$350 retail) and both are best in class in this category. Why do I own both? The answer is a combination of hubris and stupidity. I really like noise canceling headphones and I wanted to have a pair in the places I spent the most time. I spend 8-10 hours at work and quite a few more hours at home. I also liked the idea of experimenting with both headphones. I was able to get good deals (well below retail) on both headphones so I just decided I would own both and be able to write a review like this someday.
I can't say I notice much of a difference between the two headphones on this dimension. When I bought the MDX, the store clerk mentioned the sound wasn't as crisp as the QC 35, but it has “higher highs and lower lows.” To be honest, I listen to music at a VERY low volume and don't take full advantage of the dynamic range in headphones. I've listened to all (many) genres with the headphones, watched movies and listened to podcasts and there isn't a real noticeable difference.
As a side note to this section, I will say noise cancellation on the Bose is lightyears ahead of what Sony has done. I've used both on planes and during a walk and Bose just does a much better job.
I find the QC 35s to be the most comfortable headphones I've ever used. MDX are comfortable but tend to be a more fatiguing experience over a long period of wearing them. The QC 35 appear to have made a lot more decisions around comfort and just feel a lot lighter and less intrusive when using them than the MDX. I wouldn't say the MDX are uncomfortable, but I can't wear them for more than 2 hours without wanting to take a break. Both headphones share a gets sweaty when you drink a hot drink and wear them vibe. I tend to take them off if I am outside or walking around because neither does a good job of staying cool if my body heats up at all.
They have the same battery life. I can go about a week (~20 Hours) using either headphone at home or at work before having to charge them. Given the size of either pair, this kind of battery life should be expected.
In my opinion, Sony really botched their touch controls on the MDX (A tap and gesture-based control system on the right headphone). Every time I go to skip a track, turn the volume down or pause I am reminded of how bad the implementation is. I've touched the controls on accident while taking them off and putting them back on. They are cumbersome and just not good. QC35 controls are inelegant,t but I've never touched them on accident. They are not intrusive or ugly, but they aren't as cute as the MDX's. That being said, I much prefer dealing with the buttons and the simplicity they offer over the buggy touch controls.
Write here...Bluetooth is a pain to deal with. One thing I've learned using Bluetooth headphones over the years is connections will be dropped often, and make the “settings” app on iOS easily available. Bose is wise to this fact and includes the Bose Connect app. You can control your connections, pair to multiple devices (2), and even adjust your sound configurations. These additions are noticeable whenever I get home and use my QC 35s. Another nicety is the voice overs on the QC 35. The voice is much more pleasant and the feedback is a lot more useful. For example, when I turn on the QC 35s it'll announce which devices I'm connected to and I can check at any time which devices I'm connected to. Sony doesn't offer any of these features, trading them for a far simpler hold to pair set up.
The QC 35s are pretty much better at everything than the MDX. I think Sony made some interesting (bad) moves in not supporting connecting to multiple devices via Bluetooth and not including physical buttons on the unit. I don't mean to be an MDX hater, after all, I had many opportunities to return them but I kept them. Bose has been doing this for a long time and their experience shows. I look forward to future iterations of both headphones!