Hi! Glad to have found this site. I recently got a c84 free when I bought so many inks from a company. I wanted to use it mainly for printing photographs. The sharpness is good but I cannot get consistency with the colours. They are very blue and green and I have tried messing about with the advanced colour settings etc. Only limited success, the pictures tend to look false, far too vivid. Difficult to explain as Jon said. I had a c43ux and a c20 previously which gave fantastic colours although not the same sharpness.
I've tried -15 cyan, -10 magenta with some success or these and brightness +15. Overall still not happy.
Cheers