I've just finished writing up some notes on the 'True Black and White' B/W printing software for Canon large format printers.
http://www.northlight-images.co.uk/reviews/software/true_black_and_white.html
I tested it out when I recently had an iPF6300 for a review. Looks to be a good solution for getting the best B/W out of these printers
bye for now
Keith Cooper