The Redmi Note 4 is easily among the best-selling phones that Xiaomi has ever come out with, and the phone still manages to hold its ground in the under Rs 15,000 price segment even though it was launched in January. Xiaomi VP and India MD Manu Kumar Jain, only recently, announced that the company had sold 50 lakh units of the Redmi Note 4 phone in the country in 6 months since launch. The Redmi Note 4, in fact, "broke all records to become No. 1 selling smartphone in Q1 & Q2."

That despite the fact that buying a Redmi Note 4 -- like all Xiaomi phones -- doesn't come easy since the phone is almost always out of stock and when it is in stock, it sells out like hot cakes in minutes if not seconds.

On Tuesday, Xiaomi launched the Mi A1 in partnership with Google. The Mi A1 -- which in essence is a re-branded Mi 5X that was launched in China not long ago -- in typical Xiaomi fashion is a phone that's high on specs and low on price. But, it's unlike any other Xiaomi phone that you've seen before. By miles. The Mi A1 does not ship with Xiaomi's custom ROM MIUI. It's an Android One-based phone that runs a near 100 per cent version of stock Android. Wait, what?

MIUI versus Android One: The difference will be like night and day

Xiaomi's custom ROM, aka MIUI, although it offers a seamless experience across the board, is known for some heavy skinning on top of Android, something that hard-core geeks don't really appreciate. Also, because there's third-party skinning involved -- and because Xiaomi likes to update each and every device in its portfolio more or less on similar lines -- the fact that users have to wait longer for updates, doesn't go down well with many. That besides the fact that the company is known to kill some key Android features just so it can maintain uniformity across its devices is a subject of much debate.

Take the Redmi Note 4 for instance. When Xiaomi launched the Redmi Note 4 in India in January, the phone shipped with Android Marshmallow (based MIUI 8). In early August, the phone started receiving the Android 7.0 Nougat update (MIUI 8.5) alongside the July Android security patch. Interestingly, the Redmi Note 4 -- as per a Xiaomi listing -- isn't scheduled to get Android 7.1 although an update to MIUI 9 is expected to in the days to come. If Xiaomi's listing is to be gone by, chances are the Redmi Note 4 may be stuck with Android 7.0 for the rest of its life.

To expect an Android Oreo upgrade, would be wishful thinking for now. Now I am not saying that the Redmi Note 4 wouldn't get Android O at all, but, in the words of Xiaomi itself, "we don't update a phone just to change an Android version number. But, actually it has to make the phone better." Clearly, Android versions don't make a Xiaomi phone.

Xiaomi's phones, for your reference, are in no way inadequate -- or inferior -- in software standards to counterparts. It's just that Xiaomi operates in an entirely different manner . Xiaomi doesn't toil with Android AOSP APIs. Rather, the company adds its own features on top of the AOSP. A lot of this happens at the ground level which is why -- for most users -- there would generally be very little visible difference between a KitKat-based MIUI and a Marshmallow-based MIUI.

A lot of this also happens without changing an Android version. It is the MIUI version that one would see changing at all times, and going by Xiaomi's history, the company is in the habit of changing that way too frequently. Xiaomi's phones may not always boast of the latest version of Android, but, they most certainly aren't losing out on much anyways, according to Xiaomi. This also helps Xiaomi to keep updating all its phones no matter the release window.

The Mi A1 does not ship with Xiaomi's custom ROM MIUI. It's an Android One-based phone that runs a near 100 per cent version of stock Android

But there is still an audience, and a sizeable one at that, that would still take Android Nougat over Marshmallow and it would want it as quickly as possible. Xiaomi's Mi A1 Android One phone would cater well to that audience. Not only would the Mi A1 pack in the latest and greatest in Android at all times, it would be the closest thing next to what a certain Google Pixel has to offer at the end of the day: unadulterated software.

"Mi A1 is our first Android One phone, with a software experience designed by Google. We've partnered with Google to bring you a simple, pure Android phone that stays fresh overt time with OS upgrades and comes with your favorite Google services built-in," Xiaomi says about the Mi A1 in its official press release.

The Mi A1, for your reference, runs stock Android 7.1.2 Nougat out-of-the-box and will be updated to the recently announced Android Oreo by the end of this year, Xiaomi has confirmed. Xiaomi (and Google), in fact, went so far as to say that the Mi A1 will also be getting Android P - or whatever Google decides to call the Android O successor - when it launches later next year.

Unlike a certain Nokia 6, or a Moto G5S Plus, or a Lenovo K8 Plus -- that all run a stock version of Android Nougat out-of-the-box -- the Xiaomi Mi A1 is the closest it gets to pure unadulterated Google software. Both Lenovo and Moto phones ship with extra apps and features, in addition to a slightly tweaked (non-Pixel) launcher. Both Lenovo and Moto are expected to roll out Android Oreo for many of its key phones, but there's no definite time-line for the same. The same is true about the Nokia 6 (the Nokia 5 and the Nokia 3) as well. The Mi A1 Android One-based phone, meanwhile, is pretty well sorted in this regard.

FYI: Although the Xiaomi Mi A1 runs a near 100 per cent version of stock Android, the phone also ships with the company's Mi Feedback and Mi Remote apps. While the purpose of the Mi Feedback app is to let users report issues with the phone, the Mi Remote app allows users to use the Mi A1's IR-blaster. While the Mi Remote app can be uninstalled, the Mi Feedback app can't. Also, the camera app in the case of the Mi A1 is again hallmark Xiaomi. This is because the stock Google camera app can't do dual camera gimmickry like taking portrait shots, according to Xiaomi.

Clearly, the Mi A1 is the logical way forward and the obvious choice for someone who is looking to buy a Xiaomi phone and who also happens to be a stock Android fanatic. If, however you are not a stock Android fanatic, Xiaomi's MIUI offers all the bells and whistles that you'd want from a fully-functional operating system, including customisation themes. Even critics would agree, Xiaomi's MIUI is one of the better -- seamless and polished -- UIs coming from China even though it's a stark departure from Google's Android in every sense of the word.

Xiaomi Mi A1 versus Redmi Note 4: A closer look at the hardware

-- Both the Mi A1 and the Redmi Note 4 boast of full-metal bodies. Both the phones have rear-mounted fingerprint scanners and physical capacitive keys that are also backlit. Both the phones look like expensive phones, that aren't expensive at all. But, the Mi A1 is without a doubt, the more premium of the two: both in terms of looks and in terms of build quality. The Mi A1 with its all metal body and dual rear cameras may look remarkably like the iPhone 7 Plus, but, at least it looks good while at it. Also, it costs peanuts in comparison, so that's that. Everything from the 2.5 D curved glass -- which is Corning's Gorilla Glass 3 for your reference -- on the front to the antenna lines placement on the back, screams the iPhone. The only visible difference is seen in the fingerprint scanner placement. The Redmi Note 4, on the contrary is a lot less out there. It's not as solidly built as the Mi A1 though.

-- Both the Mi A1 and the Redmi Note 4 are 5.5-inch phones. Both the phones boast of a full-HD 1080p IPS LCD display panel. The Redmi Note 4, in addition, also ships with an in-built reading mode that turns colours to the warmer end of the spectrum when enabled. The feature is particularly useful during night.

Unlike a certain Nokia 6, or a Moto G5S Plus, or a Lenovo K8 Plus -- that all run a stock version of Android Nougat out-of-the-box -- the Xiaomi Mi A1 is the closest it gets to pure unadulterated Google software

-- Both the Mi A1 and the Redmi Note 4 have the same processor inside, which is, a 2GHz octa-core Qualcomm Snapdragon 625 processor clubbed with Adreno 506 GPU. While the Mi A1 comes with 4GB of RAM and 64 GB of internal storage, the Redmi Note 4 is available in three versions: 2GB RAM and 32GB memory, 3GB RAM and 32GB memory, and another with 4GB RAM and 64GB memory. Both the phones support expandable storage via a hybrid micro-SD card slot.

-- Both the phones support dual-SIM and 4G LTE (VoLTE) connectivity. While the Redmi Note 4 comes with a micro-USB 2.0 port, the Mi A1 has a USB Type-C port for charging and data syncing purposes. Both the phones come with an IR-blaster that can be used (in tandem with the Mi Remote app or even some third-party solutions) to control smart home appliances.

-- The Mi A1 comes with a dual camera setup on the rear -- 12-megapixel + 12-megapixel -- where one lens is wide-angle while the other is telephoto (or zoom lens). In terms of core specifics, the 26mm wide-angle lens on-board the Mi 5A comes with an f/2.2 aperture while the 50mm telephoto lens boasts of an f/2.6 aperture. This dual camera system offers 2X optical zoom and 10X digital zoom (just like the iPhone 7 Plus) and therefore should technically result in clearer distant shots and professional bokeh effects in portraits. The system is further aided with phase detection auto-focus and a dual-LED (dual-tone) flash but there is no optical image stabilisation. The Redmi Note 4, meanwhile, sports a 13-megapixel camera on the rear with f/2.0 aperture, Phase-Detection Autofocus along with a dual-LED (dual-tone) flash. On the front, both the Mi A1 and the Redmi Note 4 come with a 5-megapixel camera.

-- While the Redmi Note 4 is backed by a 4,100mAh battery, the Mi A1 has a smaller 3,080mAh battery inside.

Pricing

The Redmi Note 4 starts at Rs 9,999 and goes all the way up to Rs 12,999. The Mi A1, meanwhile, will cost buyers Rs 14,999.

Also Read: Mi A1 quick review: Xiaomi and Google's new Android One phone is good news for buyers