As an anecdote, I don't think Nest support is really useful. Sure it sounds nice to be able to control your Nest and the rest of your HA stuff from one place, adding a Nest to a HA solution has a lot of caveats. I have three coworkers who are all into HA pretty heavy using different solutions (Wink, SmartThings, and HomeSeer). All three hooked up their Nests to their HA network and promptly removed the link. The case? The Nest no longer thinks for itself when connected to another system. Things like presence and smart scheduling stop working in the Nest software. Basically you lose everything that the Nest offers so you can change the temp remotely (which you can already do through the Nest app).
Just wanted to add this feedback here.