I don't know much about the W4...
If anything, I'd just recommend you getting the SM3. From the ones I've owned or have listened to a bit...
Triple Fi? - Sold it - good, but not great. I found it flavorless and boring.
Se 530? sold it - rolled off highs, not accurate enough
Westone 3 - sold it - inaccurate bass, not into the "fun" sound. IEM should do just that... in-ear monitors should deliver a clear sound. There was nothing I can do to the Westone 3s to make them sound even remotely neutral.
Miles davis? beats etc. Not really a competitor in the realm of IEM's in the range you are looking for.
IE8 - unique sound of it's own. heavy heavy bass.
Ck-100 - fantastic detail... not enough... weight? I find myself loving being able to hear the lips of a female vocalist... but turn on some modern music and the quantity of solid bass isn't there. (quality is... just no quantity)
Pretty much whatever Genre I listen to, the SM3 conquers. It's just a more rounded IEM and it even sounds decent through an Ipod. the only pair of earphones that I've actually used with my iphone without absolutely going crazy. They are quite neutral, best separation I've ever heard in an IEM, fantastic detail.