Its hard to say, only very vague rumors. It is probably the uncertainty that gets me. I like to be informed before purchasing.
I'm not too worried about HW4. Rear mega castings would be nice, but its unlikely to fundamentally change how the car is for the end user although its likely to have slightly more interior space, be stronger and quieter.
Probably the big thing I am apprehensive above is that a later model will likely move to a Lithium Phosphate battery that will be cheaper, have thousands of cycle life, charge faster, be happy with 100% charging and be safer. Its likely to be heavier, but something like a entirely new battery chemistry in the long range would probably be a significant change. Most people seem pretty happy with the Model 3 RWD after it changed to a phosphate battery. I guess your the perfect person to ask, does battery chemistry make much of a day to day difference or a difference to your purchase decision?
But it is also about getting the car. Tesla doesn't seem to be accurate with delivery dates, Australia seems to be a low priority market.
Usually I am just excited while waiting, however, this time I seem to be a bit more pessimistic and apprehensive. I don't have a VIN, I don't have a hidden VIN, I guess I feel a bit flightly about the whole thing. I don't know if its going to come with a charger. I don't know if it will come with USS or radar. I'm not really enjoying the wait.. I don't know what I am getting or when I am getting it.