While Nest's $249 (£185/AU$330 converted) third-generation Learning Thermostat ($219.99 at Amazon.com) doesn't deviate wildly from previous iterations, this model has a larger screen and a slimmer profile, as well as a couple of new features. Specifically, it has a new sensor that's better at picking up your presence from a distance to display the time, indoor temperature or current weather forecast. It supports voice integrations with Google Assistant and Alexa, too. 

It also works with Nest's temperature sensor, released in 2018, roughly three years after this thermostat first hit stores. The temperature sensor is available bundled with the thermostat for $19 ($268 total), and sold separately for $39 each. Stick one in your kid's bedroom, the basement -- or any other spots that might run particularly hot or cold -- so you can use them as the default temperature readings for your home (rather than your thermostat's built-in temperature sensor). 

Like the original 2011 Nest Learning Thermostat, this one relies on built-in sensors to track your whereabouts along with algorithmic smarts to create a custom, auto-adjusting temperature schedule based on whether you're at home or away. You can still make manual tweaks to your settings on the thermostat itself -- or on the Nest app anywhere you have a Wi-Fi or cellular connection.

But those once-revolutionary features are now par for the smart-home course, with brands like Ecobee and Honeywell offering smart thermostats of their own designed to compete alongside Nest in the DIY market. 

The Nest Learning Thermostat is still worth strong consideration, but the Ecobee4 works with Google Assistant, Alexa and Apple HomeKit -- and it comes with a temperature sensor -- all for $249.

Design

You know how your smartphone doesn't look dated until you catch a glimpse of the next-gen model? That's exactly how I felt after seeing Nest's latest Learning Thermostat. No, it isn't a massive departure from past iterations. You'll still get that same rounded design and familiar display style. But, there are a few key changes.

You can now choose from among four different dial finishes, all for the same price -- stainless steel, black, white or copper. Nest's third-generation thermostat also has a 40 percent larger screen and an improved resolution for better all-around visibility. (Specifically, the display has 229 pixels per inch; that's 25 percent more than its predecessor, which should make for a sharper on-screen image.) And, Nest slimmed down the thermostat's profile so it won't stick out from the wall as much.

While I noticed the updated display size and resolution instantly, the "thinner" depth was much less obvious. A side-by-side spec comparison shows that the second-gen Nest measured 3.2 inches in diameter (8.1cm) and 1.26 inches in depth (3.2cm). The new thermostat is a touch bigger at 3.3 inches in diameter (8.4cm), but slimmer with a depth of 1.21 inches (3.1cm).

That tiny 0.05-inch difference in depth really doesn't make much of a difference visually, but Nest is clearly working to streamline its thermostat with each next-gen product launch. 

Features

The third-gen Nest Learning Thermostat also offers a handful of fresh features. Where previous Nest thermostats relied on near-field sensors alone (which have a roughly 3-foot range) to pick up on motion activity, this version tacks on a far-field sensor for a new function it calls Farsight. Farsight picks up your presence from farther away than earlier models, then it lets you see your thermostat's target temperature or the current time in either "analog" or digital modes from up to 20 feet away. This ensures that you can spot the time and temperature at a distance, without having to be on top of the Nest. And, thanks to the new and improved resolution and larger display, you'll actually be able to read them.

The Learning Thermostat, as well as the Nest Thermostat E, now work with Nest temperature sensors. Unlike Ecobee temperature sensors, which have proximity detectors to help determine if you're home or away, Nest's version only tracks ambient temperature. They also don't currently support voice commands, such as, "Hey, Google, what temperature is it in the kitchen?"

You can put up to six Nest sensors in your home and each one is powered by a single CR123 battery that's supposed to last for two years. Installation takes a few minutes -- just pull out the battery tab, enter the code on the sensor, wait for it to connect and assign it to a certain room like "Kitchen," or "Master Bedroom." 

After that, you can assign one of the sensors to act as the default temperature reading from the app. You can also create custom schedules for the morning, midday, evening and night from the "Manage sensors" section in the app settings menu.

For example, if you regularly cook in the evening, stick a temperature sensor in your kitchen. Since that room/area likely gets warmer during that time, you can set the "Kitchen" sensor to be the default temperature reading between 4 and 9 p.m. every night. That way, your heating and cooling will adjust around the temperature in the kitchen, rather than the lower temperature where your thermostat is located.

Nest's Learning Thermostat also offers Family Accounts and Home/Away Assist, two new features that help improve performance. Family Accounts lets users in the same household set up their own Nest accounts (instead of the shared family accounts that the company offered previously). Once Family Accounts are created, Home/Away Assist jumps into action by tracking each person's phone location. It isn't exactly the same as geofencing, as there's no geofenced range, but it does make it even easier for Nest to keep an eye on your whereabouts.