Andrew, will eye one display work properly with the 2690?
Yes (and no <g>). And I'm referring to an EyeOne Display-2 (EyeOne is a much older unit).
The matrix in most of the Colorimeters out there do not expect to be measuring a wide gamut unit as found here so the white point can be a bit off. Mine was about 500K off (not anything major but still, off). A Spectrophotometer has no such issues but is not as ideal for measuring darks. I actually measure the white point with my EyeOne Pro Spectrophotometer, build a custom white target, then use the colorimeter from there on. But I understand most users don't have both devices.
Bottom line: the colorimeter's can do a good job, it will be nice when their matrixes are updated (or can be updated afterwards) for these newer wide gamut devices. You might have to play around with WP values to get what you really desire because the target and what gets measured might be off a bit. A Spectrophotometer has no such issues but isn't anywhere as good at handling dark measurements. In the end, a specially mated colorimeter can't be beat (and was what NEC did with the LED wide gamut unit they had).
BTW, I'm seeing much more significant issues with the newer white LED MacBook's with Colorimeters. Last time I did a class, we had a student that had such a display and only the Spectrophotometer produced good results.