As far as perceived value goes, the CX550s are a match for anything in this price bracket.
Well made, good-looking and comfortable in situ, the Sennheisers offer ample reassurance that your money's been well spent.
And that impression is pretty much intact after a long and critical listen.
Solidly punchy and weighty (if you like that sort of thing) or on the rich side (if you don't), the CX550s offer fine levels of detail and are happy with any type of music.
A combination of complex music and keen volume can leave the top end rather exposed and everything else sounding slightly musclebound, but otherwise they're a dextrous and expressive listen.