I'm trying the RE-02 and im716 with an XP portable amp with the line out of my ipod that I had at home and I have to say that the amp does help the re-02 a decent amount. The soundstage grows a bit, the clarity goes up a notch, and the bass is slightly more pronounced. But the im716 benefits a huge amount. I never heard a phone benefit this much from an amp except the ER4S. Everything that can be better is better :P
Unamped, I think the RE-02 is much better then the im716. Amped, the im716 is a step above the RE-02. Since I use my ipod unamped, I will definitely stay with the RE-02 for now
