Any of the DUNU's I've owned or tried (TITAN 1 and DN-2000J) are a night-and-day improvement over the Sennheiser CX-300/Creative EP-630. Detail, tonality, speed, soundstaging will be a clear step up. If you are worried, just grab the FiiO EX1 (a rebranded TITAN 1 that is sonically identical) that is on sale for $69 on Amazon from someone who ships and sells through Amazon. Then, if you don't like it, return it. The return shipping is only $5 to $6.