I have a 20" one. If you have the money get one now. I have no regrets whatsoever. It's beautiful, the colors are vibrant and accurate. The respons is fast enough for games such as Quake and Unreal Tournament. (funny thing is that Apple rates the 20" display response time as 40ms, while the displays at my work are 25ms but show a lot more ghosting and tearing??) The wide aspect ratio is perfect. (perhaps because it's 16:10, almost the Golden Ratio)
Widescreen is just great, I'll never buy another 4:3 screen. And I'll never buy a CRT display.
Also, the 20" Cinema Display is just as good as a high end CRT, but much easier on the eyes.
For me it's absolutely worth the money!