Generally I've been quite happy with the quality of the mostly .avi files I download via torrents; certainly better than the crap dished out by "True Visions" dst.
However, since I started downloading British series tracked by The Box I've gotten some very bad quality files. For example, I ditched an episode of The Bill that was so jerky as to be unwatchable. I'm just now starting to watch an episode of Doctor Who. It's viewable, but just barely.
Is there some reason why the video quality of British shows would be worse than that of US shows? All are .avi files (mpga codec) of about 350 MB for 45 minutes of content. The only difference I can see is that the British shows are encoded at 25 frames per second while the US shows are 23.976 or something like that. I suspect this is due to the difference in frame rates of PAL and NTSC, but I'm not sure about that.