Hi Joe,
Sorry to sound like a dummy, but where exactly is the front feed and how do you use it? All I've managed to find on my iPF6100 is the single-sheet feeder up at the top. And that was a real pita to figure out, especially with most of the sheet sizes being listed TWICE - once for portrait and once for landscape. (And that's not talking about the orientation of your image either!)
Anyway, I did use some 8.5" x 11" paper from the single sheet feeder and was disappointed at the huge size of the unprintable margins with that. I have a lot of Epson Enhanced Matte paper in different sheet sizes I wanted to use up and the print quality and the color accuracy (using the new Canon Premium Matte icc profile) is really very good. But I guess I'll end up using those sheets on my Epson 2200. I might buy a roll of the Epson paper for my iPF6100 though as I really like the paper and the results.
From what I've heard, the biggest beef about the iPF6100 among users is the poor support for anything other than roll paper. It seems the available settings for anything else leave much to be desired.
Cheers!
Eldor