I have AT&T data plan with tethering. I tried tetherberry for comparsion. I get 800-900 kbps for my slowest download speeds with AT&T tethering. I only get 220 kbps for my fastest download speeds using tetherberry. I checked it on several popular speed testing sites.
I wrote tetherberry and asked if there were any settings to speed things up. They said there was nothing that could be done to increase the speed.
That leaves me to believe that either there is an inherent slow speed in their software or their servers are on a 56k dialup modems.
AT&T won't have to worry about people "stealing" tethering mb's at that rate.
