I've not owned an S3, but I'll tell you what the Droids do that the others don't. You'll love the active listening/breathing thing...it's always on and alert! You touch it and the time pops up. You open it, and for me, the three things I want to know most are on Moto's built-in widget: time, temp, battery. And each of those can be touched/flipped to get you more immediately. Way cool.
The other huge one is being able to talk to it, all the time! It's lost, or laying on the counter, or you're driving, OK, Google...and it pops up with, What? What you want? lol. You can launch apps, call, text, and never touch the phone. You can check the weather in Napa. You can get scores. And never touch it.
Oh, one more! You see something, want to grab a pic? Well, what a pain, right? How about twist your wrist a couple times, aim, and touch the screen? Yep, that fast. Faster than you can open your phone and find the camera button. In all fairness, the first Droid had a button that could be programmed to be the cam. Why that left town we don't know. But speed is back.