*The views and opinions expressed on this forum are purely my own. Any product claim, statistic, quote, or other representation about a product or service should be verified with the manufacturer, provider, or party.
We got S3's in June, and had so many problems we finally were able to replace them with S4's. I love my S4 - it's an order of magnitude better than the S3 was. I still have the original problem (missed incoming calls) but at least it's down to a manageable level (maybe 1 call out of 20 - the S3 seemed to miss almost half of the calls).
I've heard even better things about the S4 Active.
If you do this, you should notify AT&T that your sim is now in an S4. Otherwise it won't know about software updates and stuff.