I just received the AGPTEK M29 aka Benjie K3 this morning, and I'm pretty impressed with it so far. Its pretty sleek, thinner than the S5, and all the buttons are nice and tactile.
Initially I found menu navigation a bit confusing because the Back button naturally changes during playback to Up instead of Left, there's also no dedicated menu button, and you can only access EQ and playlists settings in the playback part of the menu by pressing Up, but despite this navigation quickly became instinctive.
As well as having the same EQ presets as the S5, it also has a custom EQ setting as well.
You can also lock the device by holding Up for a few seconds during playback.
Folder view still sadly shows files in the order that they were added to an SD card, or the internal memory.
The instructions claim its possible to record off the radio, I'm not sure if that was possible with the S5?
I think in terms of sound quality, it has a bit more clarity IMO, at least in comparison to the S5, but overall very similar.