Well, if 95% of the people in a position to do this think it's worth repeating this effort for IPv6, my objections aren't going to stop them. But if the majority or even a significant minority don't want to play, then IPv6 NAT is going to work a lot worse than IPv4 NAT.
What if only 5% of the people want to do this, and that 5% represents a couple of thousand people who configure enterprise network infrastructure. What if only 1% of that couple of thousand people are demanding that their router supplier supports NAT-PT. That is 20 enterprise customers that are telling their vendor to support NAT-PT or lose their business. In my experience 20 decision makers with purchasing power is more than enough to make things happen.
5. Everyone do whatever suits their needs like what happened in IPv4
Since this is what is going to happen regardless of your survey, what is the point? Some of us are interested in getting things done now because the time for big architectural changes has long past. We have to work with the resources available to us today.
And: if people start using NAT in IPv6 I will:
a. Implement ALGs and application workarounds to accommodate it
b. Not do anything, it's their problem if stuff breaks
c. Break stuff that goes through IPv6 NAT on purpose to prove a point
d. Do whatever my employer decides is appropriate, i.e. some A, some B and don't even think about C or you'll be on the street before lunchtime! You may know a lot about IPv6 network design but you don't understand survey design very well. --Michael Dillon