Hi Rocket. Obviously I can only talk for myself and I have also been in 5 years (at least!!) and emulate your stated position.
Firstly, for me, an "impatient investor" who is playing around in the CDY sandpit should really be termed a "speculator". An "investor", by definition, is not "impatient". CDY will remain a speculatory stock until they have kicked some basic financial goals.
Secondly, given you still appear to be "holding" the stock - you have not made any real "losses" - well, certainly not a capital loss.
Thirdly, given the interest rate environment of the past 5 years (in both NZ & OZ), it would be debatable whether you have made any losses on a "net yield" comparison. By the time you take both income tax and inflation into account, you would probably be sitting on a "negative yield" at this time.
To answer your question... my reasonable expectation to expect some kind of return is simply this - When I deem it to be the right time to sell my CDY holding - I expect to get an overall yield which is at least 10% (compounding) better than I would have got had I invested the capital in a term deposit - over the same period.
Only time will tell whether I achieve that, whether I achieve less, whether I achieve a whole lot better OR whether I lose the lot!! The thing is - I will be comfortable with whatever the outcome is.
In the meantime, I hope everyone achieves what they are looking for.