I've been looking at this since I had my entire Unit replaced at the beginning of September. My Electric Bill as a result of the replacement has dropped an average of 30 Dollars compared to statistics from this time last year. One of the first things I checked was the wiring scheme for the Ecobee 3 on their website at https://www.ecobee.com/ and the system would work. During Black Friday the price dropped to $198 from $249 but I had other obligations to take care of (significant other....). I already had a Phillips Hue system working, and now a new Smart Crock for my birthday pot that uses WeMo (horrible and unreliable interface, but great for cooking.) So a few days ago I decided to order the Ecobee 3. With the amount of praise this system has been receiving compared to the Nest, I figured this would be a great addition to my little set up. The unit came in Saturday afternoon, unboxed it and read the instructions which were straight to the point. The system comes with the Thermostat, mounting bracket and screws, instructions, and one sensor. The sensor can be placed in another area of your home and communicate with the main unit for temperature readings and for when someone is in the room. You can purchase additional sensors and place them all around your home if needed. I turned off the old unit at the circuit breaker, then removed the thermostat. I recorded the wiring scheme then proceeded to put the Ecobee together. From unboxing to getting the unit physically installed on the wall took between 30 to 40 minutes. Once I turned back on the circuit, the Ecobee turned on and gave you an introductory procedure. The configuration of the unit for me took the longest, for it asked various questions such as, are you setting this up for an Air to Air or Geothermal unit. I had no clue what these terms meant, but Google is your friend. Then proceeded to enter dimensions of the townhouse, how many floors, location, and wifi. You can do many of these tasks via your smartphone or tablet, but I used the head unit. The head unit has a sensor which activates a more detailed display once a person walks near the unit. When you approach the unit, it will just display the temperature. When you are close to the unit, it will then display an option to check the local weather and additional settings. The App mirrors the interface found on the head unit and has the same settings. You also have custom settings which are simple to configure. For example, my Thermostat is set to 68 Degrees when I'm home, 64 when I'm away, and 66 when I'm asleep. The unit will turn on at 6 in the morning if the temperature is below 68 degrees, then turn off when I leave for work at 7. At 5 in the evening the unit will turn back on using the Home setting and heat the house, if needed, to 68 degrees. If the temperature is above 75 degrees, while home, the AC will turn on. 75 Degrees is also the same setting I use for when I'm away and when I'm asleep. There's also a vacation setting you can use for when away for long periods of time. The unit also has a web interface that can be reached from anywhere around the world. Very similar to the Head Unit and Mobile layouts, the Web Interface is very easy to read and manipulate. There is also a window in which after 30 days of use, the system will give you a report on how it has worked in your home. This can obviously be used as a means to conserve energy or make adjustments to areas around the home where sensors are located. I also have this unit connected to my Echo Dot, but I did have to rename the unit to "thermostat" in order or Alexa to understand my command. "Alexa, set thermostat to 65 degrees", for example, and you'll hear the AC unit kick in. I also have it connected to iffttt, but for what the system already does out of the box, I don't have much of a need for that particular interface for now. The only drawback is that the app and unit are "internet dependent", meaning that the system communicates with an Ecobee server for data and commands. If you tell the unit to adjust the temperature, the info goes out to the web first, then back to the unit. I did suffer intermittent internet connectivity this weekend, and that is where I discovered the problem. There is also a review on youtube which describes this same issue. The unit can be installed without network configurations, but I'm not sure if the app or web interface will work. This was an easy setup and it just works. I'm looking forward to the type of report I will receive after 30 days with the unit. I've checked the current settings, and the unit is in "Away" mode and sensors read as "unoccupied". So far no glitches with the interface.