I've had a Galaxy S3 for a couple of days now. I upgraded from a LG Optimus, so I am familiar with the Android system. It's been a pretty good so far. They have seemed to remove the overheating problem. It's lightning fast and will do more things than I will ever need it to do. My kids both have Iphone 4S's and they like my Galaxy. It may be a little overwhelming for someone who is not familiar with smart phones. My buddy got one also and he hates it because he can barely figure out how to make a call on it!!
Get a good Otterbox case for whatever phone you get. The screens on all of them are pretty fragile and are expensive to replace.