Careful this is AK with their pricing system they just might take them.
A no bs straight up decent user interface. A decent on board eq (licence electi q if you have to).
User selectable impedance.
As much onboard ram as possible 128 or 256 GB and damn the battery life, if you have to go with a higher cap battery then do it.
Absolute clean line out output. And none of this piggybacking on the headphone out for a digital out nonesense.
2 SD cards with the ability to copy between those and ability to read an external HDD and do the same with that.
If you cannot do that for under 600 retail, don't bother trying. There are 50 other companies who will.
Warning: Spoiler! (Click to show)
That's true. I have always been intrigued by iRiver, but to be honest I was thinking of the Walkman Z with up to date screen res and SD slots, with better Audio chips. Extremely wishful thinking but hey, I would like to see what comes from this thread if anything