Although I was not looking to buy one, a recent problem with my Epson 9800 forced me to buy a Canon 8100 to finish a large printing job with a close deadline. I've been using it now for several weeks and am quite impressed with it.
The Photoshop plugin makes printing a breeze, and although not as streamlined as using ImagePrint on my 9800, it's quite doable and, coupled with its speed, even at highest quality settings, more than makes up for a slightly more time consuming workflow. Image quality comparisons between the two have shown that both printer/software combinations provide excellent, often almost identical, prints. Paper handling on the Canon is excellent, but the Epson is a little more flexible with odd sheet sizes. The Epson also wins for printing the whole width of 44" paper, while the Canon, loses about 1/8" on each side, an issue in only one or two percent of my workflow.
Of course, the biggest thrill for me is to now have both Matte Black and Photo Black inks in one printer!
So, I'm enjoying having both printers in operation and would like to hear from others using these Canons, and what problems they might fall prey to, if anyone has experienced any yet.