Jejari, like what acedriver said, it depends on your preference. However there's one point I would like to give note.

From my point of view, "GENERALLY" X600 is a better choice. It performs better in many areas compared to the e3100. The bass is more powerful, better defined, and it performs fairly for vocals too. Whereas e3100 is heavily suitable for only music; movies and gaming it's below par I would say.

The only sad thing is, the treble can't be controlled using the X600, as well as the design isn't too pleasing to some.