"Any favorite papers (both Canon and non-Canon) for the IPF5000?"
I have found that you can pretty much use your favorite paper with any of these pigment printers and get great results with a custom profile (I've got Epson 4800, 2400, HP 9180, and the Canon). The advertising hype out there about getting the best results on the new printers only with their brand is just that, hype. So use your favorite paper, get a custom profile, and print away. I do like the house brand papers from InkJetArt.com because they are available in both rolls and cut sheets as the same paper so only one profile is needed for all (I like luster-surface paper for my day-to-day printing). I also happen to like Silver Rag when I want a luster fine art paper, although do use the mat papers when I print black and white. I am anxious to try the new HP pro satin paper that is not available yet, although I don't know if it will be available in smaller rolls than 24" (unless HP comes out with a 17" printer) - may have to get a roll and cut it down. (The Canon specs says this printer will only accept a 59' long roll although a 100' roll fits just fine with 3" core so I'm not sure what that is all about - I have not printed with the 100' roll yet so there may be some other issues.)