I did some mytho A/B with clip+ and other old stuff I have. the clip has one of the narrowest width you can find (the signature is great but really soundstage is not its forte). well I put this sony at the other end of all the daps I've owned for its width is simply impressive.
I don't know the C3, but I remember a very audible bass rolloff on the ck4. are they similar?
the signature of the F886 isn't real neutral, sony will be sony. but as close as it gets for the brand IMO (old sonys were warmer, more voluptuous). I must have written something more precise a while back, but really it is a great player in regard to sound quality with a lot of treble information, when I was used to washed out trebles on my old sonys. actually sony fans might find the treble to be a little too much, that's how much more resolving the sound is in those frequencies.
what could be trouble is the "amp" power, android, and my little "tac" noise every 2secs that almost nobody is hearing ^_^.
about the android choice, my guess is that doing it that way let them use all the R&D of sony phones and save money. but I do hate those "do it all" daps. even my phone is not smart, that's how old school I am.