IMO, hard courts should be banned from the Slams. The US and Aussie Opens should go to either clay or grass. I much prefer a natural surface to hard courts. I find it a more difficult game on either surface for completly different reasons.
With clay, you are forced to think and play percentage tennis. Neither of which I am very good at (ok, it's funny when I say it, no help please). On grass, technique is everything. You have to focus on the ball and get to the net.