Pros:Great customer service, nice noise blocking, comfortable
Cons:very expensive. Could have better sound
The Bottom Line: If you have the money get this.
I've been using the QC3 for over a year now and I love them. Great build quality. It's built MUCH better than the terrible Tri-Port headphones which I believe are discontinued. The main benefit of these are the passive (noises from trains and planes) noise canceling and the comfort. These are possibly the most comfortable headphones in the market. They are very light and just rest on your ears and you often forget you have anything on. The leather on the ear covers are so soft it's a pleasure to wear these.
Recommend this product?
As far as sound quality goes it will not match the audiophile quality of headphones like the Sennheiser HD650 or the Grado RS-1. However those headphones also weigh a ton and aren't nearly as comfortable and have really huge unmanageable cords that aren't meant for portability. If you're looking for the absolute best in sound then look at the companies I mentioned but for the best compromise of weight, comfort, style, and sound quality the Bose QC3 are worth your money. And like all Bose products they come with a 30 day return period for any reason at all. I don't like Bose speakers and would never recommend those but these headphones are really nice. If you can't afford these the Bose On-ear seem to get good reviews as well. They are identical to the QC3 but without the noise cancelling.