Bill,

You're confusing "quality" with "consistancy". Quality of carbon masts can be tightly controlled even though the consistancy can be varied. You can order a high-quality stiff mast, or a high-quality flexible mast. They can lay up the same amount of cloth, but change the fiber orientation to change it's characteristics.

With the aluminum masts, they try to make them all as similar as possible, and simply allow the differences that occur "naturally" in the tapering process to change the characteristic of each mast.

Basically- using aluminum, they build the mast and then figure out how stiff it is. Using carbon they determine how stiff they want it and then build the mast to suit.

Also- how is the lighter weight boat being more sensitive to crew position an undesirable characteristic? A good crew can change their position to tune the boat to the conditions. Also- a lighter weight boat with the same hull section as it's heavier counterpart won't be that much more sensitive as the crew will still be placing their weight over the same section of bouyancy.
However- I entirely agree that a lighter boat would need a correspondingly lighter rig. The A-cats have been known to capsize to windward if the crew allows themselves to get teabagged when a gust dies out.