I installed Cyanogenmod (a custom ROM) on my Galaxy S3,and that fixed most of the issues with the Samsung software.
Cyanogenmod gave me (near) infinite updates past the end of Samsung updates, pre-installed with root access, really nice tethering support that was absent in the Samsung ROM, and (seemingly) better performance and less battery darin.
True that
I have s4 and I did not root it or flashed it for nearly a year..then one day I was filming timelapse with it on my window on 9 floor and left it for 30 sec and wind blew it..It shattered then I had to replace whole screen and housing and then I rooted it and instaled cm 12 aka lolipop..it flyes now!