I purchased an EyeOne (i1) last fall when I read that it works with argyllcms under linux. However before the purchase I didn't find information that Nvidia's drivers for linux were not to the OS standards, and so the calibration process failed because of Nvidia's closed-source linux drivers.
I bought a laptop a couple of months ago that has Windows 7 on it, and onboard Intel graphics with open specs. I don't do image editing with it, and almost never boot it to Win7 and so didn't rush to calibrate it.
However seeing your post today prompted me to get out the instrument and download the Xrite software for Win7 and install argyllcms on the laptop under linux.
The calibration under Win7 with Xrite LT software was fast and returned excellent results. I didn't count the number of patches, but it only took a couple of minutes. There's a toggle at the end of the process that allows you to see a stock image before/after calibration.
With linux and argyllcms the calibration is a command line affair that's straightforward in a linux command line sort of way. Under Windows and Mac OS-X, the LT version of the EyeOne is limited by software, not hardware, and you have to upgrade software to get the expanded use of the device. However with linux and argyllcms, the full potential of the EyeOne LT is pretty much the same as the higher priced versions, since the open source software isn't crippled. The argyllcms calibration scheme took much longer, and displayed hundreds of color patches, working up from near blacks through ascending values of r, g, and b, and then through many near white patches. Then it cycled down through neutrals from white to black and spend a lot of time with the near blacks again. Looking at the output file from argyllcms, it appears that there were 256 sets of 4 patches on one run and 32 sets of 3 patches on a second run, for a total of 1120 calibration patches assessed.
Windows doesn't support two color profiles on the same graphics card, so I couldn't calibrate an external monitor on the laptop under Windows, and couldn't even get the calibration patch to display anywhere but on the laptop screen. Linux may allow an external monitor calibration, but I haven't checked thoroughly yet. I have an idea about how to do that, and will report back if I have any success.
So first, I owe you some thanks for getting me back on the ball and getting much improved laptop color, and second, I'd say that the EyeOne is a very good buy, and an even better buy if you use an OS under which the calibration software doesn't cripple the hardware. Argyllcms is available for Windows, but I haven't tried it there. Perhaps I should, but I don't often boot into Windows anymore.
The editing software that I use under linux also picks up on the system's monitor color profile (if you've set that up), or allows you the choice of the system monitor .icc or a separately chosen monitor .icc.
Lee
I should add that this is the only device of this type I've used, and that my experience with it is obviously short term. But I have been manually calibrating screens under linux and M$ for a number of years, and can get 100% correct on this Xrite color vision test:
http://www.xrite.com/custom_page.aspx?PageID=77&Lang=en