A lot of streaming is not throttled: for example iPlayer and Spotify. People still sometimes get issues with them on Infinity, but people sometimes get issues with them on most ISPs,
Throttling of 'pure' p2p can be quite brutal, it depends on circumstances. On the rare cases I have tried I haven't seen any sign of throttling even at peak times, but it is clear from other posts that it can be really bad. I can't remember what the peak times are: check the ts&cs, I seem to remember peak covers quite a lot of the time.
Moved (with trepidation) to BT Infinity 2 for upload speed. Happy BE user for several years.