2) How come the original Galaxy S "runs fine"?
That was a pos! The gps didn't work, the performance was laughable compared to the iphone 4 at the time. How can you say this???
I had the international Galaxy S for 2 years (2012-2014) and it was really great... Then again, I was into flashing ROMs every week or so, so perhaps the original TouchWiz performance was that bad?
I think I fixed the GPS by following an instruction in XDA.... I don't remember, its been 5 years already? God I feel old