To decide which among the Microsoft Lumia 950, Sony Xperia Z5, or Apple iPhone 6s smartphones is the best buy option totally depends on your individual requirements. Though these phones do have many notable specs like enhanced processors and fingerprint sensors, they have different functionalities that can individually cater to your needs.

All the three smartphones, the Lumia 950, Xperia Z5, and iPhone 6s, sport different design and finishes. The Microsoft phone features a plastic finish with a sleeker design. The Xperia Z5 consists of a glass surface with smooth rear ends, whereas the iPhone 6s has a metallic chassis with an overall slimmer build.

As far as the design-related specs are concerned, only the Sony device is water resistant and has the ability to survive in one meter of water. In terms of display, both the Lumia 950 and Sony phone have a similar 5.2-inch screen with 3 GB RAM. The iPhone 6s sports smaller a 4.7-inch screen with 2 GB of RAM.

In terms of camera specs, the Sony Xperia Z5 leads as compared to the other two smartphones with a 23-megapixel rear and a 5.1-front-facing camera. The Lumia 950 consists of a 20-megapixel rear and a 5-megapixel front camera, while the iPhone 6s features a 12-megapixel rear and a 5-megapixel front shooter.

On the other hand, all the three devices are different in the performance area. The Microsoft Lumia 950 consists of a Snapdragon 808 chipset whereas the Sony phone has a Snapdragon 810 processor. But, the Apple smartphone feature A9 chipset.

All the three phones possess similar screen resolution of 2560x1440, 1920x1080 and 1334x750 respectively. However, the Sony Xperia Z5 stands out among the rest because of its 4K screen resolution.  The Microsoft Lumia 950 provides you with an additional security feature in the form of Iris recognition technology whereas, the Sony Xperia Z5 and iPhone 6s sports the regular fingerprint sensor.

Apart from the above-mentioned specs, the Microsoft Lumia 950 excels in terms of battery and charging functionalities. It consists of 3000 mAh battery and a wireless charging option to cater your needs while travelling. The Sony Xperia Z5 and the Apple phone consist of 2900 mAh and 1715 mAh battery.

When it comes to the operating system, the Lumia 950 features Android 6.0 Marshmallow and Xperia Z5 consists of the Android 5.1.1 Lollipop OS, upgradable to the Android 6.0 Marshmallow OS. But, the iPhone 6s sports the iOS 9, upgradable to iOS 9.3.3 and planned upgrade to iOS 10.

The Microsoft Lumia 950 has been priced for US$ 449; the Sony Xperia Z5 is available for US$ 910; and the Apple iPhone 6s is priced at $830.