I have been very pleased with the noise cancellation when traveling by plane or bus. In addition, although the headphones are not designed to cancel non-continuous noise (e.g., ambient noise from neighbours while I am in my apartment), I find that they still dampen it so that it is less obtrusive.
Recommend this product?
However, like some other reviewers, I have doubts about the build quality. The headphones are made in China. After about 10 months, small bits of plastic started disintegrating under the ear pads and falling out. I took it back to the store and got a new pair under warranty. On this second pair, after about a year and a half, the sound on the right side is cutting out.