They are cheap plastic, set crookedly, and must be pressed numerous times to work. While the MPTrip has voice recording, the Mambo-X has a remote control. However, as thin as it is it's still too big compared to the main unit. The remote should have track controls and volume and that's all. Like a lot of MP3 players, the Mambo-X is too damn quiet.
Top volume is way too low.
The sound quality is fine but forgettable. On top of all these complaints, the company still has the balls to charge two bills for it. Don't buy this thing unless you absolutely can't find the MPTrip. This turned out to be less of a competition than I had hoped it would be. The MPTrip embarrasses the Mambo-X on all points.