i have the screen protector for my new mbp and my old macbook. I never leave home without it.
I also had a sleez for my macbook but didn't use it too much. I thought it was inconvenient to put on, so i used an incase sleeve. My girlfriend used the radtech sleez for her mb all the time and its great. No scratches or anything. But it does stretches over time and its a little loose after 1 year of use. It still fits and fits tight just not as tight as it was when we bought it first.