Myself and many of my friends who own iPhone 5's have noticed weak to no signal in places where others with iPhone 4s' have strong signal. I'm with AT&T and so is my girlfriend. There have been many times where her 4s has 3-4 bars and my 5 says "no signal." Also, this doesn't seem to be unique to a specific carrier, just last night, a friend of mine with a Sprint iphone 5, had no signal while others with Sprint iphone 4s had signal. Anybody finding this to be a pattern?