@ Theta Alpha 1: I think you're overlooking a very important factor.
There is a distinction between a 'DAP' and an audiophile DAP. The Chinese marketplace is absolutely awash with cheap DAPs with impressive-looking 'gizmo specs' but that's not what we're discussing, here in an iBasso DAP thread.
As we see in, for example, Apple DAPs, they don't give a damn about capacity for ALAC files, since the majority of their custimers, across the globe, are using highly-compressed .aac offerings from the iTunes store.
And the DX50 is at an awkward place in the market, price-wise, since it is almost a mainstream price, and thus there will be many potential DX50 customers who may like to explore something 'a bit better' than the mass-market DAP offerings, but who have almost their entire music collection in highly-compressed mp3 or .aac format. For this kind of customer, a 64gb MicroSD card will easily cover most of their music collection.
But for those of us who understand the SQ difference of very high bitrate files, preferably lossless (ALAC, FLAC, APE etc.), 64gb is absurdly small. That's why Fiio are being very sensible by offering a single card slot on their relatively mainstream (but decent SQ) X3, but on their forthcoming X5, which is aimed at serious audiophiles, they will be implementing 2 card slots, so users can have 128gb (2 x 64gb) without too much concern, and then 256gb (2 x 128gb) sometime towards the end of 2014.
