All cool.  I was originally drawing them by hand too, and quite proud of my results.  

Then I found the LINZ data layer, so have been using that.  It's not perfect, but it's better than what's there.

I'd recommend you probably stop doing it like that.  I think the LINZ stuff is probably good enough, and comes with their building ID, so could potentially be matched and updated as they perfect their system.

I'm working on trying to get the same coverage as other suburbs, and doing a tidyup of everything afterwards.

"Perfect is the enemy of good"

I've found I can manually verify and add several thousand buildings a night.

Thinking about the data, I'm not even sure how much of it is actually useful.  Does anyone actually care if a building is a house or a garage?  Perhaps a little.  But in reality, most likely not.

I think your AEDs are probably an example of the good quality data, even though the out of hospital cardiac arrest survival rates are < 10%, and their value is very questionable.  Any idea where the various apps are pulling their data from?

I found a lost of postboxes that I might add later, but they're probably of even more questionable value.