Any savvy shopper should know that cell phones have areas of weak or no coverage.
Any halfway intelligent shopper can figure out AT&T doesn't have 3G or even 2G coverage that Verizon has, nor do they have the response time Verizon has because Verizon actually has folks traversing the country saying "Can you hear me now".
If you're trying to compare coverage for example in the UK, an area only about 50% bigger than Texas, and with a population density about 8 times the US it's apples to oranges.
Of course it is. The people over there vote in favor of consumers instead of companies, so their cell and internet networks are subsidized far better than ours are. Hence, their networks crap all over ours. Perhaps if AT&T had to play by their rules, we wouldn't be hearing how their network has all but collapsed since the 3GS rolled out, and talk of data caps would never come up.
I've heard about how terrible our cellular networks are in the US by my cousin's wife who's from Spain. Can't say I fully disagree with her.