From Wired Magazine's Gadget Lab blog, AT&T has had some issues this year with network congestion, particularly around the iPhone.
I hope that my employer takes these kinds of criticisms seriously. The company's response will say alot about whether it's really ready to make the transition from big monopoly phone company to provider of the modern communication infrastructure and services the 21st century demands.
My impression from my very lowly seat is that the former SBC management who runs AT&T now is much more comfortable pushing products out the door before they may be fully ready than certainly BellSouth was. If BellSouth was deciding whether to deploy the iPhone, we would still be waiting for all the network upgrades to be completed.
So, to those who complain about AT&T's network performance with the iPhone, you should be thankful it is even available, and, I dare say that Verizon and Sprint would likely face the same problem.
AT&T: The Communications Company That Failed to Communicate in 2009: