With a great price and what was, for the time, an impressive screen and specs, we were big fans of the Nexus 5. While its successor, the Nexus 6, improved on it in a number of ways, it was also more expensive and too much of a phablet for some.
The Nexus 5X is a return to a smaller screen size, but has it got the rest right? And is it a big enough improvement on the Nexus 5?
The Nexus 5X retains a lot of the Nexus 5's design language. Both phones have a matte plastic finish for one, with a fairly plain back in all one color and broken up with the 'nexus' logo running across it.
They also both have a protruding camera lens, but the bump on the Nexus 5X is more rounded and the camera itself is central, while it's towards the side of the Nexus 5.
The buttons have shifted around slightly too and the Nexus 5X is slightly longer and slimmer at 147 x 72.6 x 7.9mm to the Nexus 5's 137.9 x 69.2 x 8.6mm. But they're ultimately very similar looking phones, with the most immediately noticeable difference being the presence of a fingerprint scanner on the back of the Nexus 5X and two speakers on the front.
With a slimmer, more symmetrical design the Nexus 5X is arguably a refined version of what LG did with the Nexus 5, but there's not a vast amount to choose.
Front and center, there's a 5.2-inch screen on the Nexus 5X, which is a bit of a boost on the 4.95-inch one found on the Nexus 5. It's still relatively compact for a flagship phone though and certainly a lot smaller than the 5.7-inch Nexus 6P.
That's all that's changed on paper though, as the Nexus 5X, like the Nexus 5, has a 1080 x 1920 display. Given the size difference that does lead to a slightly different pixel density of around 424 pixels per inch on the Nexus 5X, versus 445 pixels per inch on the Nexus 5, but that's a negligible difference.
Power and performance
There was never any doubt that the Nexus 5X would get a power boost over its 24 month old predecessor. And while its hexa-core Snapdragon 808 processor may not quite make it a rival for the very most powerful phones around, it's certainly a big improvement on the 2.3GHz quad-core Snapdragon 800 toting Nexus 5. There's no difference in RAM though, the Nexus 5X is sticking with just 2GB like its older sibling.
The Nexus 5 specs are distinctly mid-range now, but on paper the Nexus 5X should be a high, though not quite top-end handset, so expect strong performance from it. The Nexus 5 still feels pretty speedy though, likely in part because it's running a bare-bones version of Android.
The Nexus 5X has had a sizeable jump in megapixels, up to 12MP from just 8MP in the Nexus 5. But that's not all that's changed, as a lot of focus has been put on low-light photography, to ensure your photos look great even in sub-optimal conditions.
That's good because if there's one thing we really found lacking with the Nexus 5's camera it was the low-light performance.
That aside the Nexus 5's camera isn't too bad and is helped in part by the addition of optical image stabilization, which minimizes the effects of camera shake. But that's present on the Nexus 5X too, along with a laser autofocus and a dual-LED flash, so we're hopeful that the Nexus 5X will have a snapper worthy of a flagship.
There's a change on the front camera too, with the Nexus 5X packing a 5MP sensor, while the Nexus 5 has just a 1.3MP one, so if you're a fan of selfies the 5X is a better buy.
Both the Nexus 5X and the Nexus 5 run stock Android. It's one of their big selling points, as they're ideal for anyone who'd rather avoid the often bloated manufacturer UI's you get and they're first in line for new updates.
As such, they have a very similar OS, but the Nexus 5X comes with Android Marshmallow, while the Nexus 5 runs the older Android Lollipop. An update to Marshmallow is likely soon, but the bigger issue is that Google and LG will probably stop supporting the Nexus 5 before too long, while the Nexus 5X should get Android updates for years to come.
The big new feature of the Nexus 5X is its fingerprint scanner, which takes the form of a circular sensor on the back of the phone.
Not only does this give you a slick new way to secure your handset, but with Android Pay starting its rollout, you'll also be able to use it to authorize purchases. If either of those things appeal, then that gives the Nexus 5X a big selling point over the original Nexus 5 and, if nothing else, it makes it a little more future-proofed.
Sadly, the Nexus 5's 2,300mAh juice pack gave it pretty average battery life, with the phone just about surviving a day of moderate use and requiring a power injection before bed time if used heavily.
The Nexus 5X should improve things here, as it has a larger 2,700mAh battery, though it also has a larger screen to power so don't expect miracles.
One nice bonus with the Nexus 5X though is the presence of USB-C, which means when you plug the phone in to charge, you won't have to make sure the cable is the right way up, as it works either way round. The Nexus 5X also supports QuickCharge 2.0 for speedier charging.
Price and availability
With the Nexus 6, Google pushed the price of its phones up to flagship territory, which was a sham,e as Nexus had previously made a name for itself as an excellent value option.
Thankfully, that value has returned this year, with the Nexus 5X starting at $379 (around £314/AU$449). That's only a little more than the Nexus 5 launched at, though it's now available from roughly £250 / $299 / AU$400 if you shop around. But you will definitely have to shop around, as Google has discontinued it from its store.
A lot has changed in the two years since the Nexus 5 hit the scene and that's evident in the improvements found in the Nexus 5X. From a more powerful processor, to a larger screen, an improved camera, a bigger battery, a refined design, and even new features like a fingerprint scanner and USB-C, almost everything has changed, or at least improved.
But it still retains most of what we loved about the Nexus 5, from stock Android to high-end specs at a bargain-a-licious price tag.
Despite getting on in years, the original Nexus 5 is still a valid prospect, with its low price making it more of a mid-range option. On the other hand, the new Nexus 5X slots in at the high, but not quite top end of the market offering.
Article continues below