When each of the three printers is calibrated and profiled properly it's exceedingly difficult to see any substantial difference in print quality between them.
Yes, there are difference if one looks closely. Slight different gamut, maybe a bit more shadow detail here or there, but ultimately you could mix up a pile of prints, and in a doiuble blind test never be able to tell one from the other with any degree of reliability.
I believe that except for pixel peepers (dot peepers?) the issue now is price, reliability, availability, ink costs, head clogging, size, paper handling and the rest.
By the way, I am currently testing the brand new HP Z3100 (12 ink, 24", built-in spectrophotometer) and this applies to it as well, except that the advantage of the gloss enhancer is clearly visible.
Michael