I had a Sansa Clip 8gb and it started to struggle with battery life, annoyingly I found it was the USB socket on my pc after I sold the player. I bought one of these off Play as a replacement, expecting it to be like my old one, but better. It isn't. Firstly the battery life is about half of the old one and the other thing is that it seems to lock up for several seconds when trying to play some mp3s. The old one did that too, so I guess there is something up with a few of my mp3s, but this one does it more often and the pause is longer.
Unless you need the larger memory (8gb is a lot of music anyway), I'd get the old one.
The old one is the best player I've used, including Sonys, iPods, cheapies etc etc, and this is almost as good, but the battery life isn't ideal and the lock ups are a bit annoying.