This is an update written in October 2022 of my original review in August 2022.I have downrated this thermostat to 1 star. This product does not work. I have two of them, so I know that it isn't just a bad unit, the product itself has multiple software bugs that renders it unable to operate in anything approaching a correct manner.If you look at the enclosed image you'll see just one example of it not working. You can see two instances where the thermostat turned on the Air Conditioning even though the room was already below target temperature. In addition to this problem, I have seen the following issues, in order of how disturbing it is to me and energy wastefulness:1. The thermostat will ignore when it is in the "off" position and will continue to cool the room to what would have been the set temperature (you read that right -- and yes this is ludicrous!)2. Sometimes the thermostat will choose its own air conditioning temperature that is lower (i.e. more energy wasteful) than what was set. You can cancel it, but a few minutes later it often goes back to its made-up lower temperature3. If you use any of the smart features it will only allow a 1 to 4 degree difference for the setback temperature. For me I want a 10 degree set back temperature to save money, but it only sets back by 3 degrees. So my air conditioner will run all night needlessly.4. Smart home automation often will result in the thermostat displaying the temperature or state you set but in operation it will ignore the command. (I haven't fully figured this one out, but what I do know is that I couldn't figure out how to solve my issues using smart home automation, it just wouldn't do what I told it to).5. Reporting of historical data on the web dashboard will often be incomplete, which is only really an annoyance because I've been trying to figure out what is going on, and it would be nice to have the data!The result of these bugs is that I got an electricity bill for $675, when the previous month's (with similar weather) was $415. The Ecobee raised my bill by 50%.Not only should you not buy this product, it should be banned from the market, all existing units should be recalled, and the FTC should investigate. It is false advertising that this is energy saving. Frankly it is false advertising that this is a thermostat altogether.===============================================My original review: (August 2022)Headline: You have to choose between wasting massive energy or being uncomfortable every morning for 2 hoursThe product concept is terrific - the thermostat and its remote sensors have motion sensors built-in that let the thermostat automatically switch between "Home" mode (you set your comfortable temperature for this mode) and "Away" mode (you select a setback temperature for this mode).The software implementation is flawed in a way that makes it impossible to get it to do what you would want. Unless you're in a super special situation you want the thermostat to switch between "Home" and "Away" according to the motion sensors - if it detects motion it instantly goes into "Home" and if it stops detecting motion for a certain time period it goes into "Away".Unfortunately that's not how it works. There are two problems:1. Motion-based switching between "Home" and "Away" mode has waits of up to 2 hours depending on the situation (I explain below)2. The temperature you choose in "Away" mode isn't actually used in most situations (I explain below)Motion-based switching between "Home" and "Away" mode=====================================================The time to switch between "Away" and "Home" based on motion (this is called "Smart Switch") is dependent on what mode is set in the schedule as follows:- When in scheduled "Away": Smart switch to "Home" requires 2 hours of motion- When in scheduled "Away" but currently smart switched to "Home": Smart switch to "Away" requires 2 hours of non-motion- When in scheduled "Home": Smart switch to "Away" requires 2 hours of motion- When in scheduled "Home" but currently smart switched to "Away": Smart switch to "Home" is instantaneousSo that's incredibly confusing!!!! To make things worse there's a scheduled "Sleep" mode which has its own rules for time to switch to Smart Home or Smart Away.So as you can see the only way to get instantaneous switching of the mode to "Home" based on the motion detector is to set the schedule for "Home". But every time you have the schedule switch to "Home" your system will run for 2 hours even though there is no motion because that's how long it takes to activate "Away" mode. So you have wasted 2 hours of energy every day unless the schedule time you set for home mode is exactly the time you want your system to kick in. (But hey if you just are using it based on a schedule but not the motion detector you can use a $15 thermostat with a dumb timer, you don't need the Ecobee).The only way to avoid 2 hours of uneccessary running of your system every day is to schedule "Away" mode. But then you will be up and about, activating the motion sensor for 2 hours before your system kicks in. Have fun sweltering or freezing for those 2 hours every day!Away mode temperature isn't actually used in most situations============================================================All of the above is bad enough. But it turns out there's another "feature" that gets in the way - the thermostat doesn't want you to have to wait forever to get to the temperature for "Home" mode when you're in "Away" mode. So it only allows the temperature to change by 1 to 4 degrees, depending on how long its noticed recovery takes for your house. So if you're "Away" temperature is 10 degrees different than your "Home" temperature, it doesn't matter. You only get the 1 to 4 degree difference.The result of this is that your system will be running all the time even when you're in "Away" mode. 1 to 4 degrees isn't much of a setback, so even when you manage to get into "Away" mode you won't save much energy vs having your system just on.I live in Las Vegas and currently its very hot, even at night. My house has multiple air conditioning units, most of which should be running only part of the day when there are people in the particular part of the house. All of the air conditioners are now running 24/7 because a 2 degree difference doesn't even come close to being enough to turn them off. I'm probably using 3x the energy for AC vs my previous method of manually turning AC on and off manually based on occupancy.Another problem that I had that you are unlikely to care about==============================================================I had one more issue that most people won't run into. My house has 5 (yes 5!) thermostats. They are all in hallways but we don't care about motion there, we want to know if a given room has motion. So in the app I disabled the motion detector on the thermostats and only enabled the ones on the remote sensors. Apparently until a month ago this would have worked fine. But Ecobee added a feature called "enhanced" that means even if the thermostat is disabled in software it actually isn't. This seems like a bug to me, but hey what do I know? The result is that even when rooms aren't occupied my A/C turns on because people walked down the hallway. My solution was putting a piece of electrical tape over the motion sensor on the thermostats. Not beautiful but it seems to work. Ugh.-----------------------------------My experience with customer service-----------------------------------The customer service people were terrific - kind, patient, and fairly knowledgeable. When things weren't working I called customer support and I was elevated to level 2 and then to level 3 support. My issues have now been submitted inside Ecobee as feature requests. If they fix these things they will have a truly terrific product.Just so everyone knows I am also forwarding this product review to Ecobee. Hopefully this writeup will help them understand more clearly the flaws in their product.-----------Conclusions-----------Such a shame! I desperately want Ecobee to fix these issues so I can change this to a 5 star review.In my previous house I had a Nest thermostat, and it didn't work for me because my schedule was too variable. So I really want Ecobee to work.