I have installed and calibrated a number of monitors with the new Spyder3Elite, including a couple of projectors. It has been on both Windows and Mac machines, including OS X 10.5. After a slight issue with the software not seeing one of my monitors, everything is working perfectly.
There are two things that really suprised me. The first was the profiling of a projector, which in the past I would have done with a much higher cost solution. Results were excellent with Spyder3. I then tried to profile the LCD projector against a blue-gray wall rather than a screen, I was amazed at the quality of the profile on this background. The other thing that impressed me was when running Spyder3Elite against my professional graphics display and its bundled calibrator; the results were almost identical.
This is what I would call absolutely remarkable quality from a device that retails for less than 300 dollars. As I said before, this will be what I will be recommending!