I have now started the fading test of the Canon OEM bottled inks in comparison with other inks. See this.
As the Canon G-series printers use print heads that are modified combined print head/sponge cartridges, I think the bottled Canon inks are very good refill inks for the Canon 2 cartridge printers. I will also test that.
Don't do it. Ink for Epson printers, genuine or not, is not suitable for use in a Canon printer. Epson and Canon use different printhead technologies, and different ink properties are needed for the two printer brands.