Google's brand-new Pixel 4 just launched - but here's why you should consider buying the Pixel 3a instead

Like the Pixel 4, Google's cheaper smartphone also supports features like Night Sight for taking clear photos in the dark.

The Pixel 3a lacks the secondary 16-megapixel telephoto camera found on the Pixel 4, but it does have a 12.2-megapixel main camera that's similar to that of the pricier Pixel 3 and Pixel 4. When I tested the Pixel 3a XL's camera alongside that of the much pricier iPhone XS Max several months ago, I found it to be just about on par with Apple's previous-generation flagship.

How valuable those features are will depend on what you're looking for from a smartphone. But if you aren't a photography enthusiast and don't care much about the extra flexibility you get when shooting with the Pixel 4, you can still expect to get a great camera with the Pixel 3a.

Motion Sense lets you perform tasks such as switching between songs or lowering the volume of your alarm without actually touching the phone.

Since this radar-powered tech can detect when you're nearby, the Pixel 4 also unlocks slightly faster than its cheaper sibling.

The faster face unlock is useful, but in its current state, it's also not as secure as alternatives like Apple's Face ID. The Pixel 4 may unlock even if someone were to hold the phone up to your face while you were sleeping, for example, although Google says a fix for this is coming soon.

The ability to unlock your phone slightly faster is Motion Sense's best and most practical use case, but it's not a must-have feature that drastically changes the experience of using your phone. The Pixel 3a also has a fingerprint sensor on its back unlike the Pixel 4, providing another means of unlocking your device if you choose not to use facial recognition.

While the Pixel 4 generally lasted for one entire day during my regular daily usage, the Pixel 3a XL would last a whole day and well into the next.

That may be because the Pixel 3a XL has a larger 3,700 mAh battery compared to the Pixel 4's 2,800 mAh battery, but it's important to remember that there are many factors that can impact battery life.

The Pixel 4 also comes with other minor upgrades that will likely make the phone feel a little bit faster, like 2 GB of extra memory compared to the 3a, and a screen that refreshes at a higher rate of 90Hz under certain circumstances. The Pixel 4 also runs on a faster new processor than the Pixel 3a.

With the Pixel 4, it's clear that Google is looking for new ways to make our phones feel more useful in an era in which most new devices come with incremental updates. But until features like Motion Sense are able to add more meaningful improvements to the way we use our mobile devices, the Pixel 3a is probably a better deal for most people.