Here it is... I have had an iPhone 3,3Gs,4,4s,5. And they all are good phones. I've had an anti-Apple time and bought Samsung Infuse, Galaxy Note, Galaxy s3 etc. I have all Apple computers etc. So, of course I want everything to work flawlessly. Blah Blah Blah right? The issue is there is a social app that is developed only for Apple, and that's the only reason I stay with the iPhone. It is real time talk, and it helps me talk to clients and co-workers from other countries when I need help with web hosting and WordPress troubleshooting.
Day-to-day functionality, I would use a Galaxy s3 in a heartbeat. It's a nice quality phone. Better yet, I bought my mom the Note 2, and that my friend is the best! Big screen, and it's just an all around quality phone.
I know this is a ramble session. But, iTunes and being married to a computer to sync music is double the work. And unless you jailbreak your phone then you can't function outside the box, like work in the guts of the phone. In my opinion, I would get the Galaxy s3.
I have yet to hear 1 bad thing about the S3.