Did you know that different companies come up with the final data differently? It seems shocking at first but this is one reason why we recently saw X-Rite introduce a new metric (XRGA standard). So while it was useful to use a better reference grade unit (the Minolta), there could be some differences here just due to the way two companies report the data. Having a higher end X-Rite reference instrument would make the test results a bit more accurate. Can you specify the colors or are they a fixed set? Being able to specify the colors is useful. Many “validation” processes we see are fixed and often, the companies select colors that are easy to produce low deltas.
I'm quite aware of the difficulties do this with a perfect result. I tried to find a way to spot the calibrators that gave a decent result and those who failed badly, that is that they showed an average of more than Delta E 5 or a maximum of more than Delta E 10. We have tested both EyeOne Pros rev A, B and D and they all passed. And when we compared the monitors when we used a profile created by those calibrators that failed and compared them with the profiles that were created by the those that passed, there were no problems to decide which monitor was profiled with the bad calibrators.