okay, I had this problem for the longest time. this mentality of "which one is better?"
at the end of the day, the specs, although different, won't make a difference in daily use. I live in NA but bought the International version straight up. Why?
Firstly, I don't need LTE. Internet speeds on my phone is not important.
Secondly, my service provider didn't have the S3 so I would have had to switch and pay a lot more monthly.
Thirdly, since I can't connect to LTE, it saves battery life. Not by a lot but an extra few hours always helps when your out and about or studying late at school.
I have played around with the NA version and can not tell the difference in speed at all.
So really, it's up to you.