I am so very impressed with the Bose QuietComfort Ultra Wireless Noise Canceling Headphones! The clear sound - combined with the world-class noise cancellation- deliver an unmatched audio experience. The headphones were really easy to pair with my iPhone. However, there is an insert that provides step by step instructions for those who may need it. Furthermore, you can personalize almost everything to your liking in the Bose Music app! These headphones have a long battery life of up to 24 hours. They have a quiet mode where the highs hit harder and the bass drops the deepest, an aware mode for you to hear music and your surroundings with full transparency, and an immersion mode that combines full noise cancellation and Bose Immersive Audio for the realest sound you can get. Whats more is the CustomTune technology that auto-adjusts the sound performance to the unique shape of your ears and adapt to any distortion. They personalize to always provide the best sound quality. These headphones have a revolutionary mic system allowing you to hear and be heard on calls. The headphones have soft pads that surround your ears, providing unrivaled comfort! They are made of luxe materials and provide maximum comfort. They mange to look modern, sleek, and sophisticated while doing so! I’m all about taking good care of my stuff, so I love the carry case that is included. It’s a hard-shelled case which offers optimal protection. These are easily the best headphones I have ever had the pleasure of trying, I can not recommend them enough!

-- Overall a decent product, but disappointing customer service and poorer tip fitting compared to the previous version of the product --

I own a previous version. I liked it very much and decided to purchase another set due to shortened battery life after years of use. Blocks out background sound well as many others describe.
However, I wanted to return the product, because I found the silicon tips of the earbuds do not fit as well as my older set does - the tips of the current version have slippery texture and don’t seem to seal as securely as the old one does. Also, the different sizes of tips that are included in the headphone set come in non-resealable plastic rather than in tiny zipper bags as the previous version did - with the old set, I could try all the sizes to see which size fits the best and if the product is worth the money before I decided to keep the product, but with this new set I could not open and try the tips of different sizes because if I opened them I could not seal back - the plastics that held tips were not resealable, and I thought it might be an issue if I wanted to return the product.
I couldn’t return the product however. Best Buy claimed it was not returnable due to hygienic reasons. I wish they would indicate such condition clearly when customers make purchases (I checked their return policy after declination of my return request, and saw they do state in the policy that open headsets are not returnable); the product was wrapped in a thin plastic wrapping when I received it. So if you open the outer plastic wrapping to try the product, whether you like it or not, It cannot be returned.
To sum it up, similar good quality of noise-cancelling but the poorer fitting of tips to ear compared to the previous version and the customer service.

I have owned 3 sets of these Bose headphones in the past. I have always felt they were 5 star. Bose no longer manufactures and/or repairs these Quiet Comfort QC20 headphones. I was happy they were available on EBay. However, they work but I do not believe they are authentic. The battery only last about 7 hours. My previouss ones, bought directly from Bose, last about 18 hours with noise cancelling on. Also, the sound quality is not as good as my original ones. But, the priice was OK and I now have wired headphones that are pretty good.

I bought these headphones 4 years ago. I've used them for multiple travels and used them at home on a regular. The other day, I thought about testing my products batteries because of curiosity. I played music at the 2 notches below maximum volume (don't want to blow speakers) and ran it for as long as possible. I got 17 hours and 34 minutes. After 4 years. I understand that this product is not cheap, but the all sources say "up to 16 hours". After 4 years of usage, I was able to get this product to last 17 hours and 34 minutes. This makes this product the only product I've ever found to "do better than advertised".

Sound : I'm no audiophile like when I was younger but from over 15 years of listening to music and appreciating rap music, rave music, drum and bass and productivity work music; I can honestly say that these earphones produce good sound. Would they compare the same with the best of the best for clarity and tight bass? Probably not, Bose tune headphones for the general public, they're not meant for music production.

Durability : These are corded and should be treated as such, I work in quite controlled professional environments so I don't really run into durability problems with any of my products but I would not recommend taking this to the gym.

Comfort : The design is good, it does not fall out of my ears, and it's very compact so you don't have a lug a small box around with you unlike headphones.

Value : Although expensive, I have chosen to use these QC20's over my noise cancelling headphones because it does almost the same job and with great sound. This product is probably the greatest investment I've ever made to my travelling gear arsenal.