I finally had to replace the maintenance cart in our iPF8300 and weighed it, to get an idea of how much ink was in it.
Works out at around one full 330ml cartridge's worth. Looking at how much ink I've used since getting it (I don't print high volumes of prints, but the printer is left on), I see that the printer has used just under 10% of ink for setup and cleaning. Adding a further guestimate of the setup use, brings this figure down to 6-7% for actual print work.
Very (very) much back of the envelope calculations, since I don't monitor ink usage to any fine degree, but I was wondering if the figures made sense to other users of Canon iPF printers?
A few pics and background info:http://www.northlight-images.co.uk/article_pages/printer/canon_maintenance_cartridge.html