I have the Cowon J3 -- purchased it in March 30, 2011, according to Amazon. Got the 32 GB version. I can confirm it works with .aa files, though I've never used bluetooth with it. Did know it had bluetooth, to be honest.
It's a really good player; I bought it for the file browsing capabilities and the drag-and-drop and it's a good sport.
It's got some quirks. The expandable micro SD card slot is great, but once you put a card in there, it's NOT coming out without pliers. The other issue is that if you put it on "pause" for longer than a few seconds (like, say, someone drops by your desk to talk), it will either turn off entirely (NOOOOO! TAKES FOREVER TO TURN BACK ON.) or go into "sleep" mode, depending on the settings. Sleep mode is easier to wake from, but you are NOT going to have the battery life they proclaim once you set it up to sleep instead of turn off.
I definitely get a full day out of it and could probably wring two, but I pretty much have to charge it nightly. Fine by me.
I've been using it daily since I bought it and I'd buy it all over again if I lost it. So... 4 stars?
