I recently picked up one of these. Even though, the seller told me that it's X10(not X10_S) version of the player, I guess I got the X10_S version. The track skipping buttons work when the device is locked, and the wheel can be used to adjust the volume. It also comes with a custom Eq setting like Crazier R3. Sad part is there was no Silicon case or earphone in the box. I really wanted that case. I also find the buttons and wheel to be slightly creaky.