I have been where you are. Bored with iOS and want something fresh and more controll. But the iPhone is a great product, and so is the GS3. How do I know? Because I have one. Yes, I took the plunge.
The GS3 is jammed packed with features and will be upgraded to jellybean in October. But if you get one, know there will be a lot of things you will miss about iOS's simplicity so do your research. But as for me I haven't really looked back. Maybe next year I'll get another iPhone, but so far I'm nit impressed with iOS 6.
GS3