I'm using a 20" version of that, DVI on the iMac and VGA on the Macbook and Xbox 360.
Great display. Not had much reason to upgrade from it since I bought it years back.
I didn't actually know there was a UltraSharp version of the twenty! That's sweet. What I love about mine is the varieties of outports, making it able to have most of my devices hooked up at the same time.