The SmartThermostat with Voice Control is Ecobee's new high-end smart thermostat. At $249 (including one temperature sensor), the price is steep, but Ecobee gave this model some additional smarts that make it worth considering. The Ecobee4 will continue to be sold for $249 as long as supplies last, and while the new model isn't the most dramatic upgrade over the previous one, it has the following additional features that make it more compelling:

• A glass finish rather than a plastic one
• Support for 2.4GHz and 5GHz Wi-Fi, not just 2.4GHz
• Digital rather than analog microphones (this allows better Alexa integrations)
• Improved speaker quality
• A redesigned temperature sensor 

You can't see the majority of these things by looking at the Ecobee SmartThermostat, but they do make it easier and more enjoyable to use overall. 

If you already have the Ecobee4, I wouldn't run out and buy this model, since they're very similar. But if you're interested in a solid smart thermostat with a fully functioning built-in Alexa speaker, Ecobee's latest iteration is your best bet -- and the reason I gave it an Editors' Choice award.

Read more: How to install the Ecobee SmartThermostat with Voice Control | Ecobee4 thermostat review | Nest thermostat review

A brief history of smart thermostats

Ecobee was among the first of the smart thermostat makers. Now in its fifth iteration with the SmartThermostat with Voice Control, Ecobee is Nest's key competitor in the industry. While Nest dazzled customers with cool design when it introduced its first smart thermostat in 2011, Ecobee quickly moved ahead in terms of features, offering a remote temperature sensor before Nest and innovating more quickly with features like a built-in Alexa speaker.

But even more than the Nest, the SmartThermostat with Voice Control is really competing with its predecessor, the $249 Ecobee4. Let's see how they compare.

Trying it out

I didn't notice any significant differences between the design of the Ecobee4 and this new SmartThermostat model. Both have the same rounded square shape, which Ecobee calls a "squircle," both have a glossy black faceplate -- and both have an LCD screen.

Ecobee tells me the Ecobee4 had a plastic faceplate rather than this model's new glass finish, but again, I couldn't really tell, even when I tapped on the new display to make a selection; it looks and feels the same.

That said, I did notice improved touchscreen responsiveness. All the selections I made on the thermostat screen itself worked on the first attempt, never requiring two or three tries. I can't say the same for some previous Ecobee thermostats I've tested.

The SmartThermostat also works with 2.4GHz and 5GHz Wi-Fi, whereas the the Ecobee4 only worked on 2.4GHz networks. This is great news for folks with dual-band routers, but it didn't make a significant difference in my testing. In a reviewers guide Ecobee sent me, it said this dual-band Wi-Fi support should allow for "faster and more reliable network connectivity," but I noticed no great difference. I connected to our 2.4GHz network, as I have while testing previous smart thermostats and the result was the same -- a responsive, reliably connected thermostat.

The Alexa features added to the SmartThermostat help distinguish it from the Ecobee4 more than any other changes. That starts with the digital microphones Ecobee put in this new model, versus the analog microphones in the Ecobee4. This upgrade makes the SmartThermostat better at hearing you, including offering Echo Spatial Perception or ESP at launch. ESP means that when you say "Alexa" to begin a voice command, only the closest Alexa speaker responds.

ESP worked well for me during my testing. Note: The Ecobee4 has ESP too, but it wasn't available at launch.

The SmartThermostat has better sound quality, too. Not only does that mean your interactions with Alexa will be easier to hear, but also that you can reasonably use the SmartThermostat to play music, podcasts and so on.

Of course, whether it makes sense (or not) to listen to music from your thermostat will largely depend on where it's installed. My thermostat at home, for example, is in a random hallway -- it definitely isn't a spot where I'd want to play music. But if your thermostat is installed in a more open area, an Ecobee SmartThermostat could be your go-to for playing podcasts while you cook, asking questions about the traffic or the weather and controlling smart home devices, all with simple Alexa voice commands.