I used Samsung j5 for last 3 months and my experience with this is very bad list of defects:-
first of it hang too much
when we start a WiFi and connect to any WiFi network it get automatically locked
when I type a message to my friend the space button get hanged and the whole device works but it get hang on the screen
network problem it doesnt caught network in my house
and sound is very slow we cant hear a song perfectly