I had Galaxy and exchanged it for the iphone. I have been droid my whole life and never had a problem. I had the GS3 for 2 weeks and went through 3 brand new phones. The no sim error message happened on all three. I wouldn't recommend it.
SAME EXPERIENCE , from simple mototola razor flip phone to iPhone is a shock, costs high, no instruction book and poor reception in this area, adds up to unhappy pappy