I have used both, but It Is a very hard call to me.. Mojo sounds a bit darker imho, DTR1 Is more airy and "open" (?), Detail retrieval Is almost on par, maybe a tad more present on Mojo, soundstage again to me Is more Wide on DTR1, but again you Need a good pair of headphones to really get differences of this kind, imho.
Having said this, Mojo Is Always something to be stacked with, DTR1 Is about same size but you basically won't Need anything else.
DTR1 idea, to me, Is to concentrate on SQ and driving power, getting Song from an SD, and move around with light and small setup.