I purchased a NEC2690 display with SpectraView software earlier this year after my LaCie Electron Blue CRT displays started showing their age. I don't question that it's a very good, properly calibrated display, and it shows me information in my images that i didn't see before. But that brings up other issues which I never before encountered. With my old monitors, once I tweaked an image, it would look good in e-mails, on the web, in 4 color printing, and on my client's monitors (depending on how far off their's were), and I would get close results from outside labs using their printer profiles.
Now, when I send an image to a client in an e-mail or upload to the web, it's far too saturated. And when a client views an image on their monitors, I sometimes have to explain that the file looks great on my properly calibrated monitor, even if it doesn't look perfect on theirs. (A funny side note, I used to have this issue with transparencies on different light boxes, having to explain that my MacBeth was more accurate that their cheap box). I'm actually feeling the need to drag my images over to view on my MacBook Pro display as a quick check to make sure they aren't too saturated.
So, from a practical standpoint, what good does it do to have all this information available to the photographer if only he can see it, and it doesn't all show in a printed piece, and less importantly on the web or e-mails?