I would advise you to spend some time with them. They will grow on you especially if you listen to bass heavy tunes. Many an iem fail to impress only to become favorites. That was the case for my MP8320 believe it or not. At first it sounded good to me but not mind blowing great. I kept on listening to them and the rest as they say was history.
I think if the SHE3580 had better build. Cord and came in a nice box perhaps they would impress more but if you keep listening to them they very well could become a favorite for you..Get past their cheaper looks and build and start listening to them with your tunes.