This product has several advantages over the freeware utilities that do the same thing. The largest advantage, though, is the most important; it's supported. That's why it doesn't crash Expose and why it works with 10.3, unlike just about every other utility. It has an intuitive interface, and it's stable. As OSX changes, xBack keeps up with it. This utility is maligned and given unfair one-star ratings because it costs money. Well, if you don't want to pay for it, type the terminal command every time you want a desktop screensaver. It's certainly not hard. Me, I'll pay a little for convenience and the stability denied me by the freeware apps.