I got an iPF6350 for testing - it's really a cool printer, it has huge gamut, clean, vibrant colours, nice contrast and virtually no gloss differential, but...
Am I doing something wrong, or does it have coarser screening than x880/x900 Stylus Pro series? I've set the quality to "highest" possible, the print goes reeeeealy slow, but I can easily see the screening pattern (Hahne Baryta, Canon Semimatte), and it still looks much worse than "SuperFine" setting on my 7880, not to mention "SuperPhoto"...
Yes, at absolute maximum resolution for each printer, single pass printing, the Canon is a little slower. I tested this extensively with an 11880 vs the 6100 and at maximum resolution for the Canon (600dpi, 32 pass, unidirectional, precision ON) I was getting about 8.5 square feet per hour vs the 11880 (2880dpi, uni-directional) at a little over 12. Neither of those are fast, but in all equivalent quality settings the Epson is the faster printer, unless you go to a pretty low quality (300 dpi standard bi-directional) which is very fast (133 sq/ft hour) but the Epson doesn't even have an equivalent setting and certainly the quality was unacceptable for top notch work. But I never feel like I needed to use those settings, lower quality settings are still outstanding and completely acceptable for both printers, so personally I feel the speed comparison is a wash.
As to seeing the screening, I
think I can see it but I have to look really really close (with reading glasses), and even then it's so subtle in only shows up in a few small areas. With a loupe not so hard to see.
The Epson is a 360/720 dpi based algorithm that can lay down 2880x1440 individual droplets per square inch at 3 different sizes. The Canon is a 300/600 dpi based algorithm, and lay down 2400x1200 per square inch. I'm not sure about variable dots on the Canon. The Epson has a slightly smaller minimum droplet size. This calculates out to 4.1 million dots per square inch on the Epson vs. the canons 2.9 million dots per square inch. Now I'll be the first to admit that 2.9 million dots and 300 dpi is really really good and from any normal viewing distance isn't a problem. But in printing some very large prints from my p45 a few years back, I always thought the Epson output just seemed a little "cleaner". Perhaps thats the screening, which is incredibly important part of the technology, perhaps it's the resolution or maybe some of both (or maybe I just imagined it). But the 24x72 pano that hangs in my office was printed on my Canon, and I have no problem with it.
As mentioned they both can produce really great output, and the quality of the output from either has as much to do with the files and skill used in preparing the files than anything. After using both for about a year, I prefer the Epson and sold the Canon, but that's just personal preference. I don't knock either one, they both have strong points and weak points.