I'm pretty sure that the Nexia stuff is just if you don't already have something that can talk to it over ZWave. I'd be surprised if I couldn't just add it to my Vera Lite controller and get it working the way it's supposed to. But if it needs to talk to my heating/cooling system in a way that I can't provide with the equipment I already have, I'd be hesitant to get it.

I don't know how to tell what would be compatible with my HVAC system. All I want is something that will work with it, but also has ZWave in it. Apparently the Vera will work with Insteon and X10 products too, but those all seem to be even further behind, technologically.