I bought one of these and it only lasted a year before it became incapable of playing any tracks. On the upside, the USB pen-drive design allows you to easily drag the files onto the device in the first place but more importantly when the device fails you can at least rescue your music and put it on your PC until you have bought a new player. It did corrupt some of my files so I would recommend that you keep your music files backed up on PC anyway.
You can't fast-forward or rewind through tracks, only skip to the next track, and I never did figure out how to create albums because it just seemed intent on playing all 600 songs I had loaded in a random order - but never mind, the element of surprise when you're lying on a holiday sunbed can be rather nice, and that's really what I wanted it for - holidays.
Like other reviewers I didn't find the radio function worked at all well. On the plus side, the batteries lasted quite well.
I would say this is ok if you just want a cheap device for occasional use (like holidays), but if you are going to plug it into your ears every day on the commute to work I suggest you invest in something a bit more reliable with a bit more control for the user.