I've had both, and the W3's have a warmer overall sound than the Coppers (when paired with any of my Sony daps or iPod Touch). The W3's can sound horribly sibilant if you don't get the right fit, whereas the Coppers are easier to fit and don't require so much fiddling around with. The W3's tend to have a more aggressive and livelier sound signature than the Coppers, which was really noticable coming from the IE8's.
I liked the W3's a lot (I bought them three times!) but in the end, I moved to something brighter sounding for my Sony X. From a 'sparkly highs' aspect, I don't think the Coppers or the W3's will give you anything remotely similar to the CK10. But they do both have decent sparkle, it just doesn't take centre stage like the CK10. The Coppers are a softer and smoother listen than the W3. I like quite a lively sound, which is why I chose the FX700's over the Coppers.