I advice you to install Full Advance 5.1.1 from here: https://xdaforums.com/galaxy-s3-mini/orig-development/rom-advance-5-1-1-t3324827
It's also a omni 5 based rom, but it's much more responsive. (some say this is the fastest rom out there for our phone).
Thanks man, maybe will try or just but other phone ;]