I'm interested in buying these phones, I would like to hear some opinions - by the way I listen mostly to electronic music.

Go over to http://www.head-fi.org and search for Super-fi Pro 5. Most users seem to think the Shure E4 or E4c (different colors, same phone) sound better, and that the Super-fi lack bass, which you probably care about with electronic music. Shure apparently has a newer line of IEM phones that might even be an improvement.