Dazz - my point was you seemed to be suggesting it was just an A cat thing when I believe it happens in most classes.
My observation is that the top sailors do buy new boats regularly in most classes. They either believe changes may have some benefit or a fresh boat may be a slight advantage. Agree that it is a good process to feed the second hand market.
There are some real bargains in F18's in AUS with the current slump in numbers sailing. It's just a cycle though and with enthusiastic class members pushing the class it will come back.