If traffic shaping is employed on torrents, it certainly isnt having any effect on my downloads.
My connection speed is typically around 500KB/s, and I downloaded over the weekend at full speed.
This was on O2 (LLU).
EDIT: I just had another thought. I was on BE, then moved to o2, which is basically the same backbone. It might be that because mine is an old connection, it is unhindered by traffic management. I remember reading that newer connections are cheaper, but are subject to traffic management. This is why I have stuck to the same £18/month broadband plan and havent switched to a cheaper plan.