Wayne Cosshall at The Digital ImageMaker made a review and comparison of both the Epson 3800 Pro photo printer and the HP Z3100 large format printer, only because they were at hand, although they belong to different classes of professional printers altogether.
Itâ€™s not an even comparison obviously, but Wayne did a good report on his findings after putting the two printers to their paces.
His verdict: both printers produce stunning photos (printers that cost an arm and two legs should do that). Where the HP has it all over the Epson, he says, is in swapping between matt and gloss papers, where the Epson spends a lot of time (and possibly ink, and thus money) purging. Wayne notes that the days of photographers in his native Victoria, Australia automatically choosing Epson printers are over.
Check him out with his well documented comparison, complete with photos of course, at his website.