Brainwavz M2 will beat the heck out of the IE2s for $60.
They have a similarly shaped warm, dark, and bassy sound but are much different in that the bass is very detailed and the mids are much smoother and slightly more forward. I can't say much about the highs because although the IE2s lack in detail, the M2s are slightly recessed and lack sparkle and extension.
I have owned (owned, returned after 3 days with burn in) the S4s (not s4i), which are basically the S4is but without the mic/headset functionality and phone compatibility. They gave a very "V" shaped sound. There was overemphasized bass and a big hole where the midrange is supposed to be. The highs felt extremely fatiguing and gritty or raspy. Sure, there was detail but I couldn't cope with it, having to takes breaks from the sheer fatigue of hearing such bright sounds.
I reccomend the M2s much more.
