I fly frequently and was drawn to these headphones due to their sound cancelling capabilities. I was not disappointed. These are the best headphones I have ever owned. Having used them on dozens of flights over the last few years they consistently block out the noise of the aircraft (and a large amount of noise from the ubiquitous screaming child). The reproduce treble crisply on most music types and films and give a strong level of bass. They are comfortable, sitting over the ear, and may be worn for hours at a time. They fold into their own case making them portable and come with attachments for different audio devices (including those annoying two pins that you need for a plane). Despite these headphones being extremely good, though expensive, they do have a small, long-term drawback.

After a couple of years the plastic on the headband started to deteriorate. Over the next 18 months the plastic of the headband became more brittle and fractured. The sound quality remained unaffected but the headphones were nigh on useless as they would no longer sit on the head as the headband was broken. This was not covered by warranty as it was over 2 years (EU limited warranty is 2 years and under). However, to Bose's credit, they did offer a trade in for the new model (the QC 15) for a discounted price.

In sum, truly excellent sound quality with particularly crisp treble but over the long term whilst the sound quality remained the headband disintegrated rendering them useless. I would still highly recommend these headphones.