Well, ergonomics level, this is absolutely not the top, Cowon is well known for this defect. Tags are very poorly managed, if at all. For those who want to install a different drive than the manufacturer, no problem with Android.
Then, no Google Play. I have not tried to install it for not taking my head with stories of Google account, I directly installed apps from apk files retrieved from an Android phone with the mobile app App Backup & restore (great, this app when I found I made a big whew !, no problem for my Z2).
So not great in features, but my priority is sound, and I'm ready to make some concessions for it.
So: Nickel for me, for you to see.
To avoid all the little worries, you can go on iMachinChose, but as I wrote, my priority was the sound ;-)