I had the AC guy come out to do the yearly AC tune ups. (I live in Phoenix, 2 units).
Now my house is barely two years old. He came in and told me the capacitor was shot.
Later on, he told me that due to new EPA regs 60% of his calls are for new construction homes and capacitors. Due to the regs, some sort of oil they were using is now banned and they had to go to a new capacitor that you can expect to stop working every three years or so.