Yeah, swing stick takes a while to get used to it, but once you do, it's a great feature and makes it feel like you're really hitting instead of just tapping "A" or something.
To use the batter's eye, press the left thumbstick. You'll see a little grey "eye" appear... move it to wear you think the pitch will be. If you guess right, you'll see where the ball will end up, outlined in white. On these "meat balls", you have a better chance to hit the ball, especially for homers.
I finally got the Moonshot achievement btw - Brad Hawpe hit a 456 foot blast to center field!