This seems like a slightly obvious question,
Is there a good free ISP guide for nz?
In every other country I've lived in there has been one and whilst they are never perfect, a comprehensive list of any service is always of great use when choosing.
My only guess is there hasn't been enough willing contributors in nz to make it work?
**** EDIT****
Apologies for not writing this post as comprehensively as i should.
I have googled and the only sight i have found is http://www.ispfind.co.nz at first glace is VERY outdated, take a closer look and there is some useful stuff but it no significant upgrades since 2006, biggest problem is no fibre and no VDSL so not very good for comparisons.
Whilst these forums are great for seeing other peoples thoughts on service they aren't very good for comparisons of what is offered at what prices.
Another good resource is https://www.truenet.co.nz/articles/august-2013-broadband-report but again not much of a complete buyers guide.