The sound quality of these headphones is outstanding and well worth the £90 pricetag. They produce a very balanced, even sound and bass has depth without distorting. Sound-wise, pairing it with the Sony Xperia Z and Sony's Walkman app is a joy to the ears although I am having some compatibility issues with the buttons in the Walkman app. Hopefully that'l be upgraded soon as they worked perfectly on the Galaxy Note I had before.
The flat cable means no tangles which is awesome. The buds fit snuggly in your ears once you've figured out that they don't sit like normal in-ear headphones.