I had the stepdance long ago and I liked it. Now I have my O2/ODAC and I like them pretty good as well, it's definitely an upgrade, but I still don't carry it around with me. I use it for listening sessions at the library or desk, and I want a more forward sound than my LCD2.
I was making a statement about adding amps that change the sound, and amps that cost as much as full-sized desktop amps. He does claim he loves the sound right now, so I'm guessing the upgrade he wants is the dynamics, detail, instrument separation, etc. which comes with a very transparent amp since it won't change the sound.
This is the key point. As you know, the Stepdance does not change the sound signature at all. It is just a black background with greater clarity and transparency. I don't like amps that alter the ES5 sound (and I have tried many that do).