I own a Canon 6600, and have played around with the 4200 the one before the 4300. From what i have read they are near enough exactly the same printers. I have to say the Canon does cut it with me. I have been a big lover of epson printers, but the new stuff thats comming out with canon just blows the epson out of the water. The ink is half the pirce of the canon, but dont be fooled, you get half the ink in the cartridge.
I really like my canon, and if printed on Branded paper, the results are stunning. Yes you do have to fiddle with the settings to get used to it. With regards to the sperate inks, you will notice a slight difference in shades and tones, but not a great difference. One advantage the canon has, is that it prints down to 1PL (Pico Liter) which means the ink is tightly packed. Also the print resolution is higher. For me this won me over and i am very happy.