Itz been 2 years my son is using Samsung Galaxy s4.In this period he has faced my issue such as Sometimes Phone restart randomly, Gallery crash everytime and Battery drains faster.And one of the worst issue happend with my son was The screen of samsung galaxy s4 gone Black.
If thiz happens and mobile is not in warranty then you have to spend minimum 6000 rs for just changing the display.In that 6000 rs you will get duplicate display not the original one.As thiz problem only happen with me , not will my friend as he is also using Samsung galaxy s4.But from my opinion in the price of Samsung galaxy s4 you can buy 2 smartphones .