Just got my DX100. I listened to Phil Collins Take Me Home (a song he had already pre-loaded) and it sounds pretty good. Sadly I do not have a good ear for that music and it was a 320kbps MP3. Right now I am taking off his music and uploading mine. Sadly I cannot spend too much time for it as I have to head off to class. I have a feeling I will be a little late though
The only negative I have so far is that the amp is a little weak for the Mad Dogs but it does power them at a very listenable level.
I have the same issue with my modded T50RP, I opted to get an external amp - Portaphile 627 to amplify the current hungry and inefficient T50RP :)