almost all TVportal "contributors" are in Europe - particularly eastern Europe where copyright lawyers and their lackeys have no recourse.
You can do a IP lookup on the various dotcoms, etc and see where they are in particular, eg Switzerland, Romania, Moldavia, etc.
Generally if I get too much buffering from one site, I simply move on to the next one in the list after noting where I am in the play time and simply move the playback to that spot at the new connection. I rarely have the same issue from all of the possible sources. Typically, some sites always sux and others are generally more reliable.