updated my DX50 FW to 1.2.5 without a problem, rebooted instantly.
put some flac music into internal memory.
that's all for now, wife waiting and angrily asking what i am doing there.
a couple of observations:
a) system update takes bit more time than on AK100, patience needed. update process looks a bit irky, you need connect to again and delete image update manually. still i found no problem.
b) graphic screen resolution and quality is clearly inferior to my RWAK100 and Cowon S9, no comparison here.
SO FAR GOOD IMPRESSIONS... the make quality is great, work condition is good, no single glitch so far and i happily keep fingers crossed. only screen resolution is a bit disappointing but nothing major that would make me unhappy.
c) operation wise no issues, but too fewer setting options around.
now next step will be listen and comparing to RWAK and amping.