According to a story in today’s Business Insider, website it has long been thought that the iPhone design had something to do with the poor performance on the AT&T network. However until recently AT&T has kept quiet about it.
According tot eh article “Apple rejiggered how its phones communicate with AT&T’s towers. As a result, ask the phones now put less of a load on the network for such simple tasks as finding the closest tower or checking for available text messages.” Translation: Apple made changes to fix some of the problems that the iPhone was causing for AT&T’s network, no rx which was resulting in crappy service.