Not only that, but I've never seen a picture of someone wearing custom sleeves where the housing and cable doesn't stick out of your ears like the infamous triplefi.10. I must fall in the minority of owners using the foam gliders, but once the ear pieces are jammed in, I can't see any housing sticking out when looking in the mirror. It's nice and sleek, abit uncomfortable for a few seconds.
I had contacted Etymotic last year regarding the ER4S and custom sleeves with concern about the change in sound quality from what I'm hearing with my foam glider tips and deep insertion. They replied back with, "There is no guarantee that the same sound is preserved from using the foam glider tips to custom sleeves, the sleeves main point is first and foremost for comfort."