This is one of the least expensive feature-packed mp3 players around but with all the bells and whistles come lots of glitches and inconsistencies. The first unit had to be returned after a software problem burned it up in the first two weeks of use. I'm now 10 months in with the replacement and have learned never to count on this unit- sometimes it works great, sometimes not at all. The WMA format support ended last month. I have never had more than 90 minutes of music on the rechargeable battery even after 10 hours of charging. With an alkaline battery it plays fine for up to 6 hours. The sound quality is good and the expansion slot is a must but I wish I would have spent a little more for something I could count on.