I am regularly on the lookout for one which plays opus/flac plus the usual other formats and has much more than 4G storage, but I fear this type of gadget will die out before long.
Or hopefully the Arduino and Raspberry type of hardware gets small enough that I can build my own (with which I will probably never be allowed on an airplane).
Or hopefully the Arduino and Raspberry type of hardware gets small enough that I can build my own (with which I will probably never be allowed on an airplane).