That unit looks interesting, but I would recommend a switcher that allows for three sets of stereo speakers, and also allows for any combination to be selected at the same time. The reason for this is that if you ever want to add a sub to your setup you can do so with a three way switcher.
In other words, the sub is connected to outputs 3, and 1 and 2 are used to switch between the other two speaker sets. The sub can be punched out, or used in combination with either speaker set.
That's why it's important to have a switcher with three sets of outputs and the ability to patch the speakers in any combination.