The Youtube channel "Geek Love" has performed a comparison between 7 popular mid range smartphones:
Jiayu S3+
Doogee F5
Ulefone power,
Oukitel K6000 Pro
Leagoo Elite 1
Umi touch
Elephone P8000
These phones share some similar specifications, as they all have the MT6753 chip, 3GB of RAM, 13MP&5MP cameras. In this video, we see comparisons about:
Design–Back cover & frame materials, buttons
Display–Brightness, color temperature
Screens–Anti-fingerprint coating
Software–OS
Battery–Battery life, battery capacity
Quick charging–Input power
Hardware–Sensors, Storage
Performance–Antutu scores
You can see the whole test in the video below but meanwhile we did a small comparison chart so you can see all details faster: