don't know about you..but i really like some extra bass punch with my music,the RE0 should be more balanced,neutral sounding and less "fun". don't get this wrong,I think that the M50 are well balanced but have just a little bit emphasis on the bass and also tiny bit recessed mids.
have you ever used IEM's before?
Yeah I used IEMs before. People sometimes say they are uncomfortable but I don't have a problem with them at all. What does well balance mean? Sorry, I'm pretty much new to all this.