Here is Fons Put’s comment:

In order to help some newspaper publishers to evaluate their instruments, I created a worksheet were they can compare spectrophotometers. Our first impressions:

• The i1PRO1 resembles the best WAN-IFRA measurements of the Cuboid with the X-Rite eXact.
• The i1PRO2 (XRGA) has a different response, we’re not advising this for INCQC measurements.
• The old i1PRO1 (revision AB) gives the same response as the newer i1PRO1 (revision D).

If you like to see the figures, take a look at the spreadsheet:
https://docs.google.com/spreadsheet/ccc?key=0Ams7miCg28HNdFdOWnVmRUxIeU9…