Cocked, locked and ready to rock is the way to go. That's how 1911's were designed to be carried. Hammer down can be dangerous, if anything.
I carry a Springfield Amory XD .45 as well, and believe it or not, you're currently carrying a single action pistol! WITH NO SAFETY! (well mine has one, don't know about yours!) The striker his held in the cocked position, that's why that little doohickey sticks out of the back of the slide. When you pull the trigger, the sear drops into the frame and releases the striker.
Carry with confidence. About every 2000 rounds, or every couple years, drop the slide with nothing in the chamber and make sure the hammer doesn't follow. Don't do it more often than that, you'll get peening on the hood of the chamber.