Many people say that the cables on their IEMs die like flies, so they want or use IEMs with replaceable cables. My experience is the opposite: I've never had a pair of headphones fail at the cables, IEM or otherwise, except by extreme abuse not induced by me (e.g. pulling the jack off tight sockets by the cable rather than the plug), and the one pair of replaceable cable IEMs I had died 4 times, none of those times fixable by replacing the cable. The last time was actually caused by the use of replaceable cables--the socket for the cable came off with the plug.
To avoid derailing the UE900 discussion thread, I'm posting this poll here for those of you who own replaceable cable IEMs: what has the replaceable cable done for you reliability-wise? Since one may own more than one such IEM this is a multiple-choice question--e.g. you may have broken the cable on one pair, had the drivers go dead on another pair, and had a pair where the connection goes bad no matter which cable you use--that would cover all the three "breaking" choices. I'd love to hear the details in a reply to this thread as well!