The always-trustworthy cymbacavum has published a telling review essaying why the DX50 may not be the player in which we should place our hope. (For a second opinion, check out Ω's review of the DX50, or head on over to headfonia for a third op.)
On the face of it, I agree with many of the interface issues cymba decry. However, the bar for audiophile players has already been set. It needs to be raised before we can judge audiophile players like the DX50 or the Fiio X3 to the same build and interface standards on which we judge mass market players.
The DX50 will not play or browse your music as flawlessly as an iPod will. But it is a good-sounding player. The question that both cymbal and Ω is asking is this: why can't the two be reconciled into a single package?