I just picked up an Ayre CX7e and am considering getting the "MP" upgrade. Ayre is backed up until the end of the year with this upgrade, but they say they have performed about 400 so far on the CX7 and CX5 units. There should be at least a few people around who can report on the effect of the change from first hand knowledge.
There have been a couple of posts on other forums with some preliminary reviews of the differences/improvements, but it sounds like this mod makes a substantial difference in the overall presentation of the unit. Now I like what I am hearing currently, so I'm truly wondering if the mod is an "improvement" or a "difference", and in what way.