TrueNet measures both National Latency and International Latency, this article compares average results for all probes by ISP for September.
The best are Vodafone for national latency and TelstraClear Cable for international latency.
This TrueNet measure of International Latency is to a server in the USA. Distance travelled affects performance, however the differences between ISPs shows other influences because the international distance is roughly the same for all ISPs.
It is interesting to compare this result with our webpage download times here
Orcon are able to manage fast webpage downloads despite these latency results, note that excluding mobile, they were last in both national and international latency measures.
Technical Note: Some network equipment is known to give ICMP a much lower priority than other traffic, this could make the results for ISPs that use that equipment appear to be slower than they really are. However, we perform a large number of pings, which should reduce the affects of routing equipment giving ICMP traffic a low priority.