Check out these two interesting mobile broadband speed test studies that just came out:

First off, a side-by side comparison shows T-Mobile HSPDA+ beats Sprint 4G speeds:
Don't Believe the Hype: Sprint "4G" Slower Than T-Mobile 3G, Report Finds

Next, and a nationwide test by PC Mag shows AT&T is best overall, with T-Mobile showing up as #2 in every region except the West where Verizon won:
The Fastest Mobile Networks 2010 - The Fastest Mobile Networks |