i've got the Ed 8 limited as well as ed. romeo. Personally i like the sound of the limited edition a little better: the bass has a bit more punch and the highs aren't as fatiguing. mind you the difference is quite small and could also be due to the fact that my ed. romeo is newer and thus hasn't finished burning in yet. Only time will tell i guess. However, looking at your collection of headphones i suspect you may find the highs slightly fatiguing. Having said this i remember reading here a while back that someone else preferred the sound of the romeo edition due to its less intrusive bass.
construction-wise the detachable cable seems to hold quite firmly and i have yet to have them detach accidentally while using them. I'm not sure if they use shure connectors as i haven't had a lotta experince with Shure products myself. I however do like the right-angled jack which to me looks quite classy. Having the in-line remote is also nice. If i am being very picky i guess my only complaint would be the quality of the wire: just seems a bit plasticky with a bit of a memory effect as well, such that it doesn't sit nice and straight when the entire cord is left dangling in mid-air. Overall i'm still quite happy with the romeo though.
hope this helps