If anyone is on Virgin then i sugest you do a search for problems in your area, because i phoned Virgin due to such a high packet lose and they said there was no problems. I did a search on google and found a problem so i called them back and they said oh yes we can't say when that will be fixed, so just because they say there is no problems in your area it doesn't actually mean its true.
People using SKY, good luck is all i will say, its a crappy download speed and they cut the speed if you download to much and playing online is seen as downloading so Sky could cut you even though you are not downloading. I've never had this problem with Virgin and i do my own fare share of downloading because of modding games and the mod size for one game is over 6GB's. I don't do torrents though, running any torrent cliant will effect your online connection or even if it seems fine it will efect your FPS.
The ideal thing to do when going online is to have as little running as possible, stop or pause all downloads, turn off any anti virus programs, stop any programs that are not needed etc etc. Basically give as much resources to the game as you can, if using fraps or any other recording program then it will help reduce lag while recording.
As Paul said you should do your homework into distance from exchange because the suppliers will not give a damn about it at all and will not tell you if its better or worse. Actually i lie, they will say its a better deal even if its not just to get you to sign up for it. Sad really because if they say its better then they should make sure its better, but how do you prove its worse to them, they will simply send you to a site to download something where no one is downloading from so the speed will alway's be good and then say your speed is as it should be.