Use anti-seize on the aluminum retaining nuts AND the aluminum caps when installing. Larry Stock has them F/S and says that seizures during removal often damages perfectly usable stems.
Only other weak spot I know of is the fact that they're aluminum! One owner on a cross-country trip at night had to wait his turn for gas, so with nothing else to do, he went around and kicked each tire to verify pressure (instead of using a gauge). On one of his 10" rears, he kicked the aluminum valve stem right off the car.
A tire store opened up a few miles away only 5 hrs later and fixed his Campy....