[Lourdes]

A couple of runs in the CX680i's and they'll be going back to the store. Couldn't get them to stay in (or at least not tightly) despite trying all the combinations of included fins and tips. Perhaps it was because of the lack of fit, but the sound quality was definitely not what I expected--even with fairly low expections for this type of headphone.

Although I am not a fan of Monster, the iSport seems to have garnered overewhelmingly favorable reviews ... is this because Monster fanpersons are buying them or can someone comment on them actually being that good?  

He meant the PMX not CX, described and linked to them but wrote CX by mistake.
I can't comment on them but I do have a pair on the way for cycling as they're open, for running I use all manner of IEM's as I prefer the isolation and it's not much of a safety issue. There are always a $5-50 flavours of the month here so try a few out and see if they work for sport too. Unlike the person above the M6 stay in my ears when sweating, but I think they sound *****.