This one probably goes without saying but the Nest Thermostat was one of the easiest add ons for the home automation setup.  They manage to work with just about every system out there and it does exactly what it says.  That being said there are a few things to be aware of.  #1 if you have a rectangle standard thermostat you will probably want to order a surround or wall palte to use to cover up the screw holes, unless you plan to patch the walls anyway.  I went with this one http://www.amazon.com/Round-Wall-Plate-Nest-Greenfii/dp/B00T3TEPT6    Connecting it into our system did have a problem on switching what was heat and A/C  If this is the case call support.  They were fantastic and we determines that the back panel actually had one bad pin.  They sent me a new one within days and we had it all set up and working.

Nest

Since we have had it installed I have been asked once to reset it but they did that via email to let us know so they could do a firmware update.  Overall very easy and the ability to change the temperature from anyway has been great.  This is probably the one piece of electronics that I have added that my wife picked up on right away.