Have been using ak100 for several months and always update myself any news about it.
It seems Iriver mentioned shuffle mode won't work out of or cross folders. It only works if all songs you wanna shuffle are in a single folde.
Perhaps we should let the cs of Iriver to know about our wishes. As the Iriver software is based on Linux, they should be able to do it easily.
Suggest that we make a list of what we want the software to be and request Iriver to do so accordingly.
By the way, very seldomly songs on my cards disappear but they show up again after restart the device. My cards are Sandisk class 10 64gb and all songs are loaded from external card readers.
Recently, I purchased earsonics sm64 95ohm updated version iem, perhaps coz of the impedance issue, this iem sound much normal than other 10-20ohm iem I had. Soundstage 80% close to amped, performance is quite well.
Besides, Vinnie of RWA mentioned ak100 max vol is the same as line out.
I tried it with my ibasso t5 amp comparing output 50/75 and 75/75 vol to amp.
Sound quality becomes clearer and open up when vol max to amp.