But have you and/or your clients compared HP profiles to MP profiles? If so I think you wouldn't describe the HP profiles as "top notch". Second notch maybe.
If the prints are a perfect match to the paintings, how much better can it get? One of my newest print customers is a very well known international landscape painter. Let's just say, he's color critical to a fault. In the past I only photographed his paintings. Before the z, he had all of his giclee' printing done by an established giclee' printer with a national reputation and clients; after the z, I am now his printer. I haven't made any comparisons to numerous other profiling systems because I haven't had to...my most color critical customer is happy.
Most of my prints until now have been of artwork. I have to prepare some prints for a show of my photos in the fall. Most of these photos will be landscapes. Perhaps I will see some deficiency in the profiles when printing photos, although I have yet to see any in the photos I have printed so far. I certainly haven't seen anything that would make me want to spend a few thousand $$$ (!) on another profiling software.
I think for 95-99% of the users of the z3100, any need for custom profiles is thankfully over.
Perhaps you could write a review focusing on a comparison between prints produced on the z3100 using the z3100's custom-created profiles vs. MP profiles so we can see the differences. Short of that, I don't know how I or most users can make such a comparison. If you do that, or if someone else has, please post the link here as I would be curious to see the results and I'm sure others would be interested as well.