Benek: Back to my original question: Are there any ISP's who stand out as outperforming others specifically on Whangaparaoa? Does the local network in that area have much to do with it or will any ISP who covers the region offer the same thing?
Local network will be Chorus unless you get connected to an unbundled exchange,
Then it's back to core network (not area related) then peering and many other things,
The question you are asking is not a simple answer due to some many factors