I've had no problem at all with this printer. No clogging at all, in particular. I've used the printer sparingly so far ~ once a week.
Overall very happy with the printer, except for ....
On the downside, the issue of switching between matte black and photo black has been more irritating - and costly - than anticipated. As others have suggested, I wish that the driver had the option of warning you if the paper selection is going to trigger an ink switch. A few times I've realized too late that I didn't pick the right paper. With my older Canon i9900 printer, I would just cancel the print immediately before any ink is laid out on the paper, and that's that. Not so with the 3800: the ink switch starts very quickly, and it doesn't look like there is a way to stop (or I haven't found it). So let's say I want to print matte black ink. The printer is ready to use that ink. So far so good. Then I click okay on the printing menu and realize ... too late .. that the paper selection in the driver requires photo black ink. So I cancel the operation. It doesn't matter, now the printer is switching to the wrong ink ... which means that I have to switch it back again right away to be able to get my picture out. A back and forth swap between the two type of inks for not even one print. Ouch!
With time I suspect that I'll learn to be more careful. But for the time being, what a very annoying feature!