Uhh... well, I would take ER4 over Skullcandy Ink'ed any day. lol
Only the very best dynamic drivers in IEMs like the one in Hifiman IEMs, IE8, FX700 and a handful of others can compete with the best single driver BAs in most or all aspects of sound quality. Most of the dynamic IEMs on the market can't take on an ER4 or SA6 though. And to match top single BAs in speed and separation it really takes the very best dynamics to do that like the RE0, RE252 and up. Anything below can't compete with the best single BAs in speed and separation, and clarity too.