I bough this to replace my Fiio X1, which had become so sensitive on the controls that I was lucky to get it to play music at all. I use these in my car, so controls that work properly are vital.
I took the 32gb card, full of my fave FLAC's out of the Fiio and put it in this, and it worked perfectly!
Controls could be (MUCH) better - I was hoping for something that would default to "Play" once turned un, not have to go into a submenu each time to start the tunes happening, but I can live with that.
Now 32gb is a bit small for my music collection, so I bought a (cheap) 128gb card. That didn't go well. Spent hours (and hours and hours) copying several thousand FLAC files to the new card (I did format it in the player first) and most files were corrupted.
I tried again, a few albums at a time, and again one album, as music files only (no folders). At first this worked, but soon after the device was only recognising < 2/3 of the songs.
Well, serves me right for cheaping out on the memory card - so today a 128gb Samsung card arrived - and while copying my whole music library in one 6 1/2 hour file transfer didn't work it seems to be coping with 7-8 albums worth at a time. Fingers crossed...