I using this application 1 month before and I face many performance and battery lag in the Android smartphone.
This application always run in background instead of blocking from background.
This application consumes hunge amount of battery.
This application also always track our location.
This application is best only for those who spend their more time on facebook because it provides nice user interface and you can easily use all features of facebook.
But to chat with friends you need to install messenger.
This application also consumes huge amount of data.
I suggest you not to install this application instead you can bookmark this site in browser.