The last game i purchased from Steam was roughly a little over a year ago and up to that point any game downloads would take days. I'm not on any kind of uber-fast connection (10mb) and never had any issues with any issues streaming or downloading content from any other service.You're the first person I've ever heard say that Steam throttled downloads, and I've heard and had a lot of complaints about Steam in the past. That's just not one of them. In fact, the only thing close to throttling I've heard is users wanting the ability to manually throttle game downloads.
I'm not saying your lying, I'm just not sure that it was as a result of something on Steam's end.