I used to have a much older model of the same range, from about 5 years ago. On the downside the older one required Sonicstage to add music to it, but the battery life was incredible, I got a Sony silicone skin for it, the controls were perfectly placed and, generally, it gave me half a decade of listening pleasure.
I expected the same or better from the newer model. Yes, it now has a simple drag-and-drop facility for adding music (so no more Sonicstage, which is a definite plus) but: controls are all over the place, not ideal if you just want to reach into your pocket and skip a song; the battery life actually seems to be worse than its pre-pre-predecessor; it actually crashes - about once a week - and I have had to put a small black safety pin around the earphone cable so I can poke the reset button when necessary (it just suddenly locks up and produces a constant, awful buzzing tone). All in all, while it is usable, it is a great disappointment and next time I will probably be looking for something else.