I had a bithead before the epc and I feel the EPC offers significantly improved sound. It's simply better all around. Just like how I told you I felt the super.fi vs the e500. Although I must admit the differences between the headphones is greater than the amp. the e500 kick butt
As far as portability I think the EPC is a bit on the heavy side and because of that I've ordered a tomahawk to play with(it's actually for the wife but i'll try it!
) and should have that tomorrow. If it's equivalent with the EPC I'll probably get that instead for myself as well.
The battery life on the EPC is great. I've used it quite a bit since I got it last week and I haven't charged it yet. I think today I may finally plug it in again.
On sound, vs the bithead it offers a lot more bass extension and overall offers an excellent, detailed, crisp clear sound. It's also hiss-free where as the bithead has some noise but nothing terrible. Suffice to say, I'm very happy with the sound the epc cranks out.
The EPC seems very powerful. Much more so than the bithead. I feel like it's perhaps overkill for IEM. I barely
turn up the volume when using IEM or even my hd595. It certainly seems like it's very versatile and will be able to power pretty much any headphone you toss at it with ease.
In summary, I had an excellent time listening to Massive Attack - Mezzanine today on the xenos and e500 coming to work today!