I am using thus device since 23 days and I am going to giving a review on vivo y66.
Screen performance-:
This phone has a 5.50inch screen which is very big and good also and you can experience a very good and the brightness of the screen is really also awesome.
Processor performance-:
It had a 1.4Ghz processor and it works very smoothly during the multitasking and you can easily task between more tha 13 apps without any hangs and there is no lags during the multitasking and run freely without clearing the apps on recent apps.
Gaming performance-:
This phone has a 3gb of ram which make you free to download any large or geavy games like gta San Andreas, modern combat 5 and many more I downled many heavy games but gta san Andrea’s hangs so much and there are many frame skips and many times it hangs bt in all other games they all runs very smoothly.
Back Camera performance-:
This device has a 13 mp camera which click a good quality pictures but not a crystal clear picture it is an average camera and it can only click photo in dayloght but in low light it cant able to focis on closer objects.
Front camera performance-
This device has a 5mp front camera shooter which also clicks an average quality of pictures and it good for closer selfies but not good for wide selfies.
Look and feels-:
This device is is very light weight mobile and the back panel doesn’t have any grip so there is a chance of sliping of the device form your hand anytime so you have to buy a grip back cover to protect it fully.
So you have only buy this phone for it only gaming performance.