Hi Sparky,
the button layout is ok but they operate differently then my Korgs and Yamaha keyboards. The big problem is the RH lead voice does not change when you press a variation button, located to the left of the player. However, with the ONE-TOUCH feature turned on, when you select a RH tone, located to the right of the player, the variation will change. Yes, it is as weird a it sounds.
In some cases a sustain pedal would help and I do have one - but it is not always useful for every sound.
Deane