I have been using this device since last 10 days and phone works fine, I did not noticed any lag or any heating issues in this phone.
pros:-
. Camera performance is above average.
. The very good thing in device is its battery it puts 4100mah battery which can easily last for 1.5 days on a single charge.
. it can play heavy games without any noticeable lag. I have tested some heavy games like asphalt8, modern combat etc
. Its finger print scanner response is very good it can unlock your device in just fraction of second.
cons:-
. Build quality is good but back is some slippery.
. Finger print scanner must be a little bit lower from the current position.
. Speaker volume is below average you cant hear the ringtone on another room if ringtone volume level is at max.
overall I would say that this is very good budget oriented smartphone.