I chose the Cowon J3 over the competition for its sound quality, long battery life and its degradable storage.
Support for FLAC and a wide variety of music files and its ability to read album art from tags was also a great thing to have.
The UI is responsive and looks nice, but it takes some time to get used to. Not all of the options are labelled or straightforward. No shuffle button for example, you have to go into your root directory and select a song at random with random turned on. Some symbols used in the options I have never seen before, and are not described in the manual.
With some playing around you come to learn about what each one does and how to use it properly.
Screen is bright and beautiful, Video playback is very responsive.
Physical buttons are also a very nice thing to have!
My main con with the device would have to be with the proprietary cable, its one of a kind and doesn’t really match the player. You also have to remove a flimsy tab on the J3 to plug it in. I don’t feel like it will break if you care for it properly but it is pretty flimsy.