Like others, I've been having a pig of a time with Orcon peak speed issues over the last couple of weeks. Calls to the helpdesk are answered with the usual rhetoric (isolate your modem, try another modem, etc, el infinito).
I also use OpenDNS at home to restrict access to unfavourable websites. When I was with Telecom, they advised me to use their own DNS to improve performance (something to do with their cache). As far as I'm aware, Orcon do not have a local cache, but could I see an improvement if I were to change back to their DNS?