It has something to do with the radios. The reception is the same when I'm at home, but at work there is a clear difference, but.......my lg revolution never loses 4g connection compared to my thunderbolt which would bounce in and out of reception. When I'm at home the download speeds are the same 17-20mb + while at work it was 17-20mb down for the thunderbolt and 10-15mb down for the revolution.
The other interesting thing is my upload speads on my lg revolution are the same or better than the thunderbolt and no matter what my signal is, it never drops below 4mb upload.
Side Note, questions need to go in the question or general section. Its pretty frowned apon to post these kind of things in the development section.