That is really interesting. I wonder if it is just volume related. Maybe there are far fewer iPhones operating on Rogers and/or Rogers had a higher available capacity to start with. Or it is a combination of these two factors. I remember when AT&T first switched over to GSM, the service was terrible. But eventually they ramped up the capacity and now it is really good. I just thought AT&T's 3g had been in place long enough to have sorted this type of thing out.

Also, doesn't Rogers impose quota's on its data plan users? This would have a big impact on keeping bandwidth available. AT&T, as far as I know, does not impose any limits on iPhone users, so they are free to hog all the bandwidth they want without any drawbacks.