I no longer follow the DX50 thread, the HM-901 thread, or the X3 and X5 threads, so I don't really know if there are any outstanding bugs with the DX50 currently, but some people are just fortunate to only use features that are working well, where others are not so lucky.
But whether you just happen to be one of the lucky DX50 users or... they've actually fixed a lot of annoying bugs, I'm happy for you, too! Seriously. It's refreshing to find someone who can even say they are content with these typically half-baked contraptions.
I'm still afraid to buy any of the current breed of "audiophile" DAPs, for not wanting to repeat the misery I suffered with the HM-801, having bought it only after waiting for their last firmware upgrade - just so that I could avoid the "growing pains." HiFiMan had already released the HM-901 and there were no more firmware upgrades forthcoming for the now obsolete (but never actually fixed) HM-801. I returned it under their very generous guarantee.