I have both models of Epson printers (9800 and 7980). I ran a test yesterday using the same photograph with Qimage and a Epson Premium Glossy paper using a proper ICC profile.
With the two printer outputs side by side I notice the 7890 is crisper and more virburent. When I bought the ink I have noted that the printers use similar ink color carts. The Vivid Mag and the Yellow are noted differences. Do your inks track these changes in color? If so can I use the 7980 colors in the 9800.?