Have you measured dark colors and compared with the i1?
What about the stability? What if you measure after 5', 10', 30', 60', 120'?
This is an example validation of a calibration and profiling that was done with "cold" i1pro:
Next validation done after few minutes, with the i1pro hanging on the screen:
I'm planning to test the influence of heat on DISCUS measurements - it should be stable in theory, as it has a temperature sensor and electronic compensation.