I'm currently failing to get anywhere with BT re a line to the new house, so I've decided that it'll be a lot easier if I just run the cable myself and the next BT engineer to turn up will just connects it both ends and buggers off. The top of the nearest pole to the intended location of the master socket is 200 mtrs, I can buy either 0.5mm or 0.9mm cable. Is 0.9mm likely to provide noticeably better performance, I'm thinking of signal to noise ratio (although there may be other issues that I haven't considered)?

http://www.fscables.com/Signal++Control/Telephone+Cables/CW1128+External+Telephone+Cable/list.htm