How is the iMac Display for Color Correcting?

I'm doing color repros, using Photoshop and need a reliable display for color correcting. I've had to dump two old CRT's recently, because they were becoming too unstable. And my old Mac is getting, well, too old. I'm thinking of getting an iMac. Is anyone here using one for similar work? Can I expect reliable color from it? Does anyone find it too dark/too bright/too pixelly/too or not enough anything else?

Not related to the display, but does anyone expect the imminent OS upgrade will be of any major benefit to me, graphics-wise? IOW, should I buy now or wait a couple weeks?