This is interesting. I have had Nest thermostats for several years, and overall I think they're great, but I have definitely felt the need for remote sensors (our upstairs thermostat in particular is in a really bad spot). A couple of months ago I seriously considered getting an Ecobee, but I read a bunch of reviews that complained of stuff like unresponsive touchscreen, bad UI, etc. The main thing I love about the Nest is that the UX is very simple, and works well. Anyone in the house can use it without instructions, and it feels like a thermostat, not a slow Android device or something.
Did you find those to not be issues? Definitely most of the reviews were good, so maybe it's just isolated people having problems. But I couldn't tell if it was that, or more that people either aren't as picky about UX as I am, or they didn't have another point of comparison... I'm very open to re-considering them if someone can convince me this stuff is a non-issue, because the remote sensor would certainly make our system work better.
I had same reservations as you before I bought my first Ecobee3. I probably read same negative reviews as you. However the thermostat worked very well for me, without all the issues that I've read. I bought two more over the year. In terms of UI and ease of use - I prefer a thermostat with which I don't need to fiddle after I program it. Ecobee3's programming and automatic features worked well for my family in two zones. Kitchen zone (used mostly by my wife) was impossible to program to her satisfaction but integration with Amazon Echo solved the issue.
Has not been an issue for me (I do have a second generation). I believe there was a firmware fix sometime down the line. Actually that is another plus, they have been better about updates than Nest. My Nest actually stopped working on more than one occasion after a software update.
My thermostats are in areas that are not indicative of the actual room temperature at all so the sensors are useful for me. I don't have a more complicated setup with dampers to divert air to a specific room, but that could be a cool addon if they made it compatible.
I've had an ecobee 3 since November, and the UX has been very responsive and intuitive to me. My wife can use it well enough to set manual away and temperature overrides, which is pretty much all that you might need to do after you've set it up. The android and ios apps are nothing special, basically just a clone of the thermostat's UI itself, but they work. The web app is very good, and the graphs are very nice and useful, including the ability to export all data as a csv. I've never used a Nest so I don't know how it compares but I'm quite happy with the ecobee.
I have the honeywell 9000 with remote sensors. While getting the internet connectivity was a little odd (you need this weird redlink device to bridge the devices for web management) They work and are remotely managed extremely easily.
They're not 'machine learning' thermostats, but they work predictably, reliably well. Cheaper than a nest, too..
Did you find those to not be issues? Definitely most of the reviews were good, so maybe it's just isolated people having problems. But I couldn't tell if it was that, or more that people either aren't as picky about UX as I am, or they didn't have another point of comparison... I'm very open to re-considering them if someone can convince me this stuff is a non-issue, because the remote sensor would certainly make our system work better.