Earlier this week, Nubia, a subsidiary of ZTE, released a new smartphone, Z9 Mini, in India.

ZTE Nubia Z9 Mini sports a sturdy metallic frame around the edges and has 64-bit class Snapdragon 615 Octa-core CPU, 2GB RAM and 2,900mAh battery enough to last for over a day.

All in all, the device possesses all required features of mid-range smartphones available in Indian market, but the only drawback is its ₹16,999 price tag. It is a bit steep compared to the popular Chinese rival Xiaomi Mi 4i and Asus Zenfone 2, which house similar features.

To provide a better perspective on these phones, we have briefly described the key specifications of ZTE Nubia Z9 Mini, Xiaomi Mi4i and Asus Zenfone 2 (ZE551ML).

The new ZTE Nubia Mini and the Xiaomi Mi 4i sport a 5.0-inch full HD display having pixel density of 441ppi (pixels per inch) and are protected by Gorilla Glass 3 shield.

One notable feature of Xiaomi Mi 4i is that it boasts Sunlight Display technology. This dedicated processor inside the Mi 4i enables the device to make changes in display brightness automatically based on the lighting conditions of the environment. It is done by brightening only the darker regions, so the resulting image becomes clearer to the users' eyes irrespective of the surroundings.

Asus Zenfone 2, though it sports an energy-efficient full HD super AMOLED screen, its big display foot-print (5.5-inch size) reduces the pixel density close to 401 ppi (pixels per inch).

All three competitors house 64-bit class SoC (System on Chip) and 2GB RAM configuration; But, Xiaomi Mi 4i and Nubia Z9 Mini have a slight edge over the Asus Zenfone 2, as they are shipped with Snapdragon 615 Octa-core SoC (System on Chip), manufactured by the industry leader, Qualcomm.

Snapdragon 615 chipset comes with H.265/High Efficiency Video Coding (HEVC) which enables faster computational operations. It is aptly backed by Adreno 405 graphics engine and 2GB DDR3 RAM.

The only drawback of Xiaomi Mi 4i is that it lacks microSD card slot for memory expansion.

On the other hand, Asus Zenfone 2 -ZE551ML (2GB RAM model) houses a 64-bit class based 1.8GHz Intel Atom processor Z3560 respectively. It is backed by with PowerVR G6430 graphics engine and expandable memory (+64GB via microSD card).

ZTE Nubia Z9 Mini ships with feature-rich 16mp camera on the rear-side with LED flash, Sony IMX234 Exmor RS sensor, f/2.0 aperture and an 8mp front camera with f/2.4 aperture, 80-degree wide-angle picture capture feature.

Asus Zenfone 2 is no less of a competitor. It too boasts top-of-the-line 13mp camera on the rear-side, backed by proprietary PixelMaster technology, Backlight (HDR) mode, f/ 2.0 aperture, and 5mp snapper on the front with 88-degree field of view and also comes with ZenUI Selfie Panorama mode, which can capture panoramic selfies with up to a 140-degree field of view.

Xiaomi Mi 4i too features a 13mp Sony/Samsung camera with dual-tone LED flash, f/2.0 aperture, auto-focus, HDR, touch-focus, full HD video recording ability and a 5mp snapper with 80-degree wide-angle lens, f/1.8 aperture with full HD video recording ability which is certain to please the selfie aficionados.

[Note: More mega-pixel count in the camera does not guarantee a good quality photograph. It all depends on the type of the lens, size and aperture.]

In this aspect, all phones stand even as they run on same Android mobile OS platform, but differ in OS version and user interface.

Xiaomi Mi4i, ZTE Nubia Z9 Mini and Asus Zenfone 2 ship with Lollipop OS accompanied with respective custom interface MIUI v6.0, Nubia v2.8 and ZenUI respectively.

Price is one of the most important aspects of this comparison article as it plays a crucial role in the minds of the price-sensitive middle-class working population, which forms the biggest chunk of the India's demography.

Zenfone 2 (2GB RAM/16GB memory) model costs ₹14,999, whereas the new ZTE Nubia Z9 comes with a hefty ₹16,999 price tag.

Xiaomi Mi 4i comes with a budget-friendly price tag of just ₹12,999 and is likely to sway more buyers who don't mind with limited 12GB (4GB used for system OS and apps) memory.