Yes, Michael pretty much sums it up.
FSX Deluxe came with NZAA as one of the 45 worldwide 'high detail' airports, which was ok, unless you knew the real airport. I don't think many still use this.
Christchurch was always the domain of Ian Warren, who produced his first version for FS2000. That was the first time I saw what could be accomplished with custom airports, and got me started in sim development. I always encouraged -- pushed, cajoled, nagged -- Ian to redo it for FSX, but it never came about.
In 2009 I had been trying to get access to NZAA, without success, so I decided to look at NZCH instead. It was in the middle of a major upgrade at the time. Access there too was difficult, and with winter coming up I can remember walking outside the boundary fence, taking photos of what I could see through the fences. The aero club was a big help, and things were starting to come together, then I was diagnosed with a heart condition, so I gave up anything stressful for a while:)
However I have recently been contracted to complete a project which includes NZCH, which will happen quite quickly, although the contract doesn't cover getting it to a 'Real New Zealand' standard. The plan is to then bring it to Real NZ standard and release it via my store. This would be part of the 'multi-sim' project funded via Kickstarter, so I aim to release it for at least one other simulator, maybe more. There's a lot of work to do before that will happen, though.
The contract is for a Prepar3d v3 version, otherwise I was considering that the next major project may be x64 only... Prepar3d v4 plus X-plane and/or Aerofly FS2. In case you haven't heard, the future is 64 bits!