NY Times article (blog): The iPhone Excuse"

[MacVixen]

In the office where I work cell reception is atrocious across all carriers. Not being able to get a signal whatsoever I ended up using very few minutes. Then AT&T put some antennas in our building, and people who had AT&T were the only ones that could get service (this did not include me). Once I switched to AT&T and got my iphone I could suddenly use my phone again (but no 3G in the building). So it really just depends on your individual situation. I get great reception at home too, with full 3G.

Putting those antennas in buildings makes a huge difference. My husband was working for Apple for about 8 months. At the time he was on Verizon and had zero coverage in the building while all of his co-workers with their iPhones were just fine. When he inquired about it, that's when he found out that AT&T (and/or Apple) had installed the extra antennas in the building.

I was a loyal Verizon customer for about 8 years and had about 0 complaints about their coverage areas and call reception. Having been with AT&T for about 6 months now... I'm adjusting. The 3G network is spotty in my area on the coast, though great when I head over the hill to San Jose/South Bay. My bigger issue was driving down I-5 from the Central Valley to Anaheim. The coverage was horrible. Areas along I-5 with NO service at all!! I just found that shocking since I-5 is such a major corridor through the state.