PC World has released their "3G Wireless Performance Tests" and they've given AT&T the highest ranking. I find that rather ironic given all the recent complaints about the reliability of the AT&T network. Maybe PC World ran their tests before the Apple iPhone spread across the 13 different cities tested by PC World. Or, maybe the editors (and testers) at PC World have a bias. Maybe these test results are very representative of the 13 cities tested. Who knows. I haven't performed 3G head-to-head studies, so I have no data.
In any case, it's an interesting study and you can read about it here. Since PC World isn't a peer-reviewed journal, I doubt that we'll see many editorials or comments regarding the study design, methodology, data collection, possibilities of bias, etc.