Update, June 1, 2018
The QuietComfort 35 II reviewed here was released in September 2017, and it remains one of our top picks for wireless noise-canceling headphones. While the Sony WH-1000XM2 arguably sounds a tad better and is more feature rich, the Bose QuietComfort 35 II is lighter and more comfortable to wear. The price for the Beats Studio3 Wireless has dropped (you can get it for less than $225 online), so it's become a more attractive option in this category.
The original review of the Bose QuietComfort 35 II follows, having bee first published Oct. 2, 2017 and otherwise mostly unchanged since Dec. 1, 2017, when we raised the design rating from 9 to 10 having reviewed its direct competitors.
Bose's QuietComfort 35 II ($350, £330, AU$500) wireless noise-canceing headphone looks, sounds and performs just like the original except for one key feature: There's a new "Action" button on the left ear cup that allows you to connect to your Google Assistant without having to touch your phone. And that makes the QC35 II -- available in black or silver -- the first headphone to integrate Google Assistant.
Similar to Amazon's Alexa voice assistant, Google Assistant is available for Android and iOS devices. Instead of talking to your phone to access Google Assistant (you have to download the free app), you just press and hold the Action button on the QC35 II and issue commands such as "Tell me the latest news," "call Mom" and "What are some good Indian restaurants nearby?" You can also use your voice to control your music playback and compatible smart devices in your home.
Here's the better news: You don't have to use the Action button for Google Assistant. Using the Bose Connect app, you can choose instead to map the Action button to noise-cancellation levels, toggling between Low, High and Off with each button press. You can also adjust the noise-canceling settings in the app, an important feature for those who may be sensitive to the feeling of light pressure that can be the by-product of active noise-cancellation.
Aside from that new button, nothing else has changed. The QC35 has the same comfy fit, same top-notch noise canceling, identical controls on the right ear cup -- yes, you can access Siri on iPhones -- and the same battery life at up to 20 hours in wireless mode with noise canceling on. If the battery runs out, you can still use the headphone in passive mode (it sounds good not great) and you get a cord for plugging in when you need to.
Not the best sound, but among the best
As I said in my review of the original QC35, this may not be the best-sounding Bluetooth headphone out there, but it's certainly among them. In the past I've compared it to the Sennheiser Momentum 2.0 Wireless, now called the HD1 Wireless Headphones with Active Noise Cancellation, noting that the Sennhesier sounded slightly better, with a bit tighter bass, slightly better clarity and was overall more natural sounding.
Sony's MDR-1000X, which has now been updated to the WH-1000XM2, is also slightly ahead on the sound quality front. But how you feel about each headphone will be impacted by the recording quality of the tracks, which means it'll vary depending on the types of music you listen to and where you get it from.
The Bose is good at taking whatever's thrown at it and turning it into smooth, pleasant sound that's generally well-balanced with plenty of punch to the bass. It sounds comparatively excellent for a Bluetooth headphone. That said, CNET contributor Steve Guttenberg thought the Sony had a clearer, more open sound. "The Quiet Comfort 35 was no slouch," he said. "But it flattened dynamics and the sound seemed less alive. Bass definition was also less distinct than what I heard from the MDR-1000X."
I rated the Bose slightly higher than the older Sony (the MDR-1000X) because of other factors beyond the sound. While their noise-canceling was equally good (yes, Sony has caught up) I thought the Bose was more comfortable and more user friendly. However, with the newer Sony WH-1000XM2 offering better battery life, slightly better build quality and even more features -- perhaps too many -- it's really hard to say which is the better headphone. They currently have identical ratings. While the Sony has a slight edge in certain areas, this Bose remains more comfortable and works better as a headset for making calls.
It's worth noting that when used as a headset it muffles wind, crowd noise and other ambient sounds so callers can hear you better -- and vice versa. Another nice feature: While you're using the QC35 II as a headset you can hear your own voice in the headphones as you speak so you won't raise your voice.
The Google Assistant factor
How much of game changer is the direct connection to Google Assistant? After using the headphones for a week, I'm not sure. The new voice-assistant feature is one of those things that some people will appreciate and frequently use but others may never bother with it. It currently does have its quirks and limitations, but like Amazon's Alexa voice-assistant, it's evolving and acquiring new skills and will get better over time.
If you already own a pair of the original QC35s, I don't think it's worth upgrading to this model for the integrated Google Assistant. But what the new feature does do is give an already excellent wireless noise-canceling headphone a little bit more personality. And despite the fact that the performance and sound hasn't changed, it helps Bose keep pace with Sony's upgraded WH-1000XM2 and Beats' improved Studio3 Wireless, both of which also cost $350.