Upside. I wanted a cheap MP3 player that I wouldn't cry about if lost or stolen and this is fine. Decent sound, decent battery life,(so far), and it's easy to set up and use with W7. It's also nicely designed; tiny, lightweight and functional.
Downside. It won't accept any of my extensive CD collection, ripped to WMA format but that's not really the device's fault and, as someone else said, you'd be foolish to buy a 32gb sd card for it unless it's permanently plugged into a PC or power supply; 3 hours of battery life won't touch the 4 gb sd card supplied with it, and you have to start from scratch every time you turn it on.
I have no idea why it has an ebook facility built in, I wouldn't fancy reading anything on a screen that size. I suppose it might be useful for transferring files.
You get what you pay for.