A bit more info: Here in Oz we are expected to pay about US$110 for a standard Canon cart. So, most locals buy from overseas sources at about $US80. I did this for a while and finally found a user of Inkjet Carts products who had a bit of time with their products.
(My Canon dealer sells so few local carts that he and other dealers told the local Canon distributor how much trade they were losing. Canon were not interested and continue to price ink so high locally that almost no-one buys it here!)
Inkjet Carts use US made inks and I found little change in color - but most of our product is canvas prints of my wife's art, so if color were to be a bit off, well, who would know. If customers like her work they just buy it. Any way we saw virtually no change.
The lower cost of Inkjet Carts ink was enough to save the cost of a print head, about $350, after about 7 cartridge purchases. As I'd had the 6100 for about 7 years and felt less intimidated by it - off we went with Inkjet Carts. After 2 years of exclusive use I can certainly say that the head life has NOT been reduced.
The only remaining risk is longevity. Is Inkjet Carts "Image Specialists" ink? Possibly, but no definitive answer. If so, it had reasonable test results from Ardenberg Imaging, with only a moderate result for yellow. My feeling is that on canvas with a liquid laminate coating you could count on about 50 years or so.
