The sound is on par with other Bose audio products, which is to say it's exceptional. Well balanced fidelity at any volume further enhanced by excellent noise cancelling technology. No matter who you are, you'll appreciate the fine audio reproduction of this product.
The outer shell is constructed from plastic that feels strong and solid. The ear and headband cushions are really soft and supple. Overall, the headphones are incredibly lightweight. Much lighter than they appear.
On the right earpiece, there is a Micro USB port for charging, player and volume controls, and a power/Bluetooth connection switch. On the left earpiece, there is the Action button that can summon Google Assistant or toggle noise cancellation. The headband is adjustable and allows for a perfect height adjustments to fit any adult-sized head.
A firm-sided carrying case is provided to protect your headphone investment. Inside is a small pocket to secure the included micro USB charging cable and the 3.5mm-to-2.5mm audio cable.
iOS APP & GOOGLE ASSISTANT
The Bose Connect app for iOS provides simple and intuitive access to the headphone's settings. There is also an Android app. Settings for the headphones include connections to different devices, the level of noise cancellation, and updating the firmware.
To use Google Assistant, you must install the dedicated app for that service on your phone. The utility you'll get from this service will depend on your comfort level with sharing just about everything (contacts, calendar, etc) with Google. I allowed full access, and the assistant works really well. Most of the questions I asked got surprisingly quick responses. I checked weather, asked a celebrity's age, and checked a flight status. When I asked for news, I got an NPR quick brief.
USE & PERFORMANCE
The noise cancellation is very, very good. In fact, it is too good in some cases. Where many noise cancelling products are able to cancel droning and repetitive sounds, the QuietComfort 35 II headphones were able silence radio and television audio and even humans talking directly to me. So noise cancellation is truly excellent.
The QuietComfort headphones earn their name. They're very lightweight and comfortable on the head and ears. I was able to listen to music for several hours barely aware they were on me. And the fit is secure. I tested them by jumping and running, and they held firmly and comfortably. That said, the materials probably are not designed for perspiration, but you can be confident they won't go flying if you have to jog up a flight of stairs.
Bose provides a 3.5mm-to-2.5mm audio cable for optional wired listening, and they work as you'd expect. However, when connected by wire to my iPhone, the on-headset buttons no longer controlled playback or volume, adjustments had to be performed on my phone. Once back on a Bluetooth connection, everything immediately began functioning again.
The headphones are easy to recommend. The sound is so complete and pleasing, you can get lost in any audio you choose. The noise cancellation will keep the world away from you, too. They represent an investment, of course. But if you're picky about sound or you're a card-carrying audiophile, you will simply fall in love with these headphones. They are truly that good.