Bruno, I got this model. So far, so good. Then again, it hasn't had to do a whole lot, since the mild weather here has meant we haven't really needed much heating or cooling.

That thermostat probably doesn't do as much, HVAC-wise, as the Nest does, but it does what we need. Our system isn't very fancy. However, I do believe I can use Vera to tell it what the outside temperature is, which can help in automating it. I could also do stuff like get ZWave door/window sensors, and tell my system that when it detects the windows are open, turn off the HVAC.

I'm not aware of any coupons. My wife and I got a 10% off coupon when we moved, and we used that on our new washer/dryer set to save a good chunk of cash.