There are a lot more changes to SL than you might think. Open these two images: Bottom on is 10.6, upper is 10.5. You'll notice that in 10.6, nearly every UI widget has been tweaked. The blue grid highlights has a slightly darker color (probably due to the gamma adjustment) Every checkbox, button, etc now has a slight shadow, the ball selector is now much smaller and rounder and darker. The arrow selector has a completely different gradient look. Most of the drop down selectors now have a *slightly* different gradient, making them more pronounced. The traffic lights at the top for SL seem less embossed and much softer / part of the UI. Flip through them, you'll notice nearly everything has changed.