I have using lenovo k4 sence 3days.In this three days I have not got any essue or any lag in perfomance.It is very very smooth in perfomance.The touch is very responcive.Very good camera clearite.But the game like Asphalt8 lag in very high graphics and its very smooth in medium graphics.In build quality the phone is very good.
This is the best ever budget smart phone with 3gb ram octa core processor and a fingerprint scanner.Finger print scanner is very very responcive.Its open less than a second.I like this phone very much.