I have just found a website of an Australian COGY agent.
It starts with a little "Bargain" look, but I found it really useful to understand COGY as I scroll down.
People has been asking me for a brochure of COGY. and I have not been able to make one yet. I may not have to make it forever, as this Australian website explain almost everything I wanted to say!
Just one thing we have to be careful is, COGY actually has 2 types. One is called "regular", the other is called "Premier" or "Differential" version. It seems that the COGY sold in Australia is regular version. and COGY sold in NZ is Differential version. One of the main wheels of regular version is detachable, but that of Differential version doesn't.
The name "Differential version" comes from differential gear system. Because of this differential gear system, pedalling does not slip off as much as regular version does. Turing right/left is smoother, and smaller turn is possible to both direction.
We decided to import only Differential-gear version in NZ. This version is much better for the price (regular version is a little cheaper), suits much better for our land and culture. Differential version does not make any problem with users dominant side (right/left), as regular version does.
Another thing you may notice is, they sell red colour in Australia, but we don't. We only have yellow colour here in NZ. It's because of Kowhai, our national flower. No, actually not. This is not the original reason, but it is a good excuse ;-P. Yellow suits perfectly with our blue sky and green grass.
I made a research on the colour of COGY. Which colour do people like more, yellow or red? I asked many healthcare professionals and potential users. Yellow won, out of question. It's proven that I'm not the only person, but majority of the relating people prefer yellow on COGY.