I have using this phone for the past three years and still works like a charm. The Samsung offers a very good hardware configuration. Not only that its performance of the hardware is appreciable. The Samsung Galaxy S3 is having soo much custom ROMs to grab on.
Even the beta version is worth a try. Custom ROM that I currently use is the Euphoria OS which is a custom version of Android Lolipop 5.1. Even though Samsung doesn’t allow user to upgrade to lolipop.