Gauntlet thrown Sir! Remember it's not a straight fight - EXT will have to contend against the Z1R/IE900 tag team
Well this is all relative to personal tastes & perceptions...but the mids were the deal breaker for me with both those IEMs.
I have a suspicion that the smackdown may not even get into the sound aspect; the fit may be a deal breaker before @gLer hits play