Infinix Hot series is one of a kind that Infinix Company keeps upgrading. After the introduction of Infinix Hot 3, within two months of sales, Infinix Hot 4 was launched. 

Infinix Hot 4 is said to be Infinix Hot 3 successor. With introduction of Android Marshmallow, XOS UI and increase in screen size, and some new features.

Hot Series: Infinix Hot 3 Vs Hot 4

Specs	HOT 4 X557	X554 HOT 3
Camera	8 Rear + 5.5MP Front flash	8 Rear + 5MP Front flash
Memory	16 GB ROM + 2GB RAM	16+1 / 16+2
Battery	4000mah + Fast charge + OTG	3000mAh + OTG
Processor	Quad-core cortex 1.3GHz	Quad core Mediatek 1.3Ghz
Screen size	5.5'HD	5'' inch HD full lamination
OS	Android 6.0	Lollipop 5.1
UI	XOS	XUI
Sound	DNC + Smart voice	Dual mic cancelling noise for clear conversation , anti sound break , RNS technology
Colors	Red, blue, champagne, green & black	Black , red , Blue , white
Voice	Smart voice	Camera voice command
Security	Finger print sensor
Network	4G LTE, 2G/3G	3G

Infinix Hot 3 has more attention in the market than infinix Hot 4 due to the little difference in their specifications

In my opinion, the Infinix HOT 4 is of a better choice than that of Infinix Hot 3, but I would like to hear your own opinion via the comment box.