What made me buy this product was the huge difference between the photos in my screen and after printing. Since I have 2 computers and they both showed similarish colours, I thought they can't both be wrong, right? Wrong. As soon as I calibrated both screens I saw a huge difference, and when comparing with the prints I already had, I could see they were much closer. Now this was to illustrate the usefulness of this kind of product. What about this product in particular?
My experience with the Eye One Display 2 was mostly positive, there was already a driver available for Windows 7 that worked without any problem and the supplied software did its job.
Although, I noticed some small bugs in the software itself. Nothing show-stopper, but a little annoying at times. Calibrating an external screen that I use with my laptop wasn't as straightforward as I thought, because even though I had set the external one as main screen and had the window of the application in it, it would still try to profile the laptop screen. My suggestion to the ones with this problem is, in windows, to disable the laptop screen, run the calibration software with the external one and then re enable the screen.
Very useful product that produces very good results with some quirks that can be easily bypassed.