The issue with the 4900 is that the tray won't close down to take the smaller stock. For this problem, which was the same with the 4000, I cut a piece of wood as a shim to fill the gap. But even having done this with the 4900 the cards won't grab properly and they end up being pulled in sideways and jamming. Also foe some reason it is more difficult to clean the rollers on the 4900, from my memory. I actually haven't tried using it in a more than a year for cards. ACI Labs print cards for about $1.40 a card with envelope, which isn't that much more then printing myself, but I have to order sets of 25, which become cost prohibitive. And I also prefer the satisfaction of creating them myself. My big question about the Epson P-800 vs the Canon Pixma Pro 100 would be how easy is it to clean the rollers? The micro powder buildup is what caused all the jams on my 4000's.