The scene and zone switch are the same device. They just have a parameter set that changes their behavior. I know this because I purchased a scene switch and what I reall needed was a zone switch. So Chris Walker told me which parameter to set to change it. I forget what that parameter was but if anyone ever needs it I'm sure its lost in my gmail somewhere.
Hmm... interesting. So why 2 different devices I wonder? Because one is a rocker and another a toggle?