I've never been throttled. I got up to around 20GB a few months back. I don't use as much now but I like that I don't have to think about it when I do. =)
I don't understand why I get throttled every month the second I go over 5GB and some never get throttled. Pisses me off even more.
I filed a complaint with the FTC. AT&T has 30 days (like 15 now) to get back to me with a reply.