I did a little research and came up with a little info about the EIZO and the ACD. I found a site that had deltaE measurements on both using the same setups. I this case a 6500K 2.2 gamma setting, I added the screenshots below. To explain these a little more about deltaE (again), it is the measurement of a monitors color accuracy, 1 deltaE is the first point a human eye can tell the difference between two tones, actual color vs displayed color. A reading under 1 is perfect, under 2 is excellent and under 3 is very good and considered expectable as a color calibrated monitor. As you look at both of the charts on the right (with the bars) you will see just about all the values under 3, the average deltaE would be in the 1s. You are looking at 2 excellent monitors. Here's my take on it, I give more weight to the grayscale side of the chart than the color side, the reason for that is a fully saturated color takes a lot of adjusting to move it to another color. The slightest variation in a color like a warm gray can easily become a cool gray. Also, the ability to see your shadow and highlight detail correctly to me is more important than fully saturated color. That said, I give the EIZO a slight edge over the ACD. The EIZO monitor that was tested is not the highest end EIZO so I would hope that the high end ones would be even better.
As side note, one of the things that the EIZO website talks about is the internal 14 bit processing (the new CG211 is 16 bit) and it's the deltaE average being 0.5. That's what happens internally, the problem is Photoshop is only a true 8 bit program and not able to handle the 14 bit coming from the EIZO, so it's translated. That's why these bars are not averaging 0.5 deltaE. While all that horsepower is great it's not used to it's fullest yet, it's real world numbers are not quite as good. The new CG211 has a 16 bit processor and claims "16-bit internal processing for grayscale rendering that is on a par with high-end CRT monitors". Interesting, what that suggests to me is the Barco is still the king of calibrated monitors, sadly Barco seems to have left the graphic arts market. I have been using Barcos for 10 years now and I found them to be stellar in color calibration.
I have links to the articles I got the charts from. It's interesting that even with these numbers they loved the EIZO and hated the ACD. One of the reasons they site is the fact that ADC can only get good calibration from a hardware calibrator. It seems like a moot point to me, to get good calibration you must use a hardware calibrator for any monitor, period.
http://www.behardware.com/articles/583-1/test-apple-cinema-display-20.html
http://www.behardware.com/articles/587-1/eizo-s2110w-the-big-come-back.html
They also have a review on a Dell but used completely different testing methods, not a good way to compare it with the ACD and the EIZO. From what I understand it's easier to get good calibration at a higher color temperature (9000) as opposed to lower ones like 5000. For the print market 5000 to 6500 is the color range to work in.
Here's another link to deltaE tests on the ACD. The results are very much the same as the tests above but they love the ACD. Funny that similar results can be so differently read.
http://www.colormanagement.nl/reports/index.php?id=5,2,0,0,1,0
Hope some of you find this helpful.