A review update for the Cowon X7 Personal Media Player. I've still really only explored the audio functions (though I did try the radio player). I have played about with four UCIs (User Contributed Interface, I think), which I believe significantly enhance the usability of the device: Lynx - An excellent desktop replacement, with useful widgets - an absolutely vital addition to the X7. It offers customised wallpaper art and a very usable interface. Sense - A replacement for the original music player, offering among other things good album art display.  I understand that the device as supplied has a bit of trouble displaying/resizing album art. Leaf - A music browser app, which is not only visually appealing but offers several search options. Vision - Photo album, less important for my purposes, and it seems to pick up a lot of cover art files (a legacy from the music collection). All four of these UCIs were written by Kizune, who posts frequently at the iAudiophile forums (indeed he may be the administrator there).  These forums are an invaluable resource for the new Cowon user.   In use, I've had a couple of occasions when something's got corrupted and the system no longer recognises the music files on the hard drive. The only sensible way I've found to rectify this is to replace the system files on the Flash drive.  I guess it might be possible to identify which files are responsible for the problem, but I haven't done so yet.  On the first occasion this happened, upgrading the firmware (in this case from 2.07 to 2.08) corrected the problem.  The second time I tried to reinstall the firmware, but it didn't help.  I then made a back up of the Flash drive and deleted the lot, reinstalled firmware 2.8 and copied back the UCIs I'd installed. This is a faff, since you have to go back and configure the device from scratch. For future use, I've made a backup of the Flash drive in a functional state, and I'll see if merely replacing the Flash drive files with that will sort matters out. I've seen reports that using a Mac for file transfer can responsible for this situation arising. I was indeed using a Mac, but it doesn't seem to happen particularly frequently - I have connected the device many times daily for file transfers and only suffered this issue on two occasions. I think I'd have to conclude that the Cowon X7 is an excellent player, but that the user needs to be prepared to fiddle and troubleshoot the device on occasion.  Fortunately, I quite like tinkering!