From personal experience I can say, without question, that the low cost "compatable" inks are definately "much of a muchness". These generic inks give wishy-washy colours with no intensity and bleed into each other quite dramatically, especially on copier paper but even on good quality photo paper. All of the suppliers of these inks will tell you they are exclusively formulated for your printer but take it from someone that used to be in the cartridge recycling business that just ain't so. I have actually stood and watched Epson, Canon, HP and Brother cartridges all being filled from the same ink tank
If you intend to do any photo printing then you are best served using original Epson inks - yeah I know they cost more per gram than gold - or you'll spend all of your time trying to find ways to match the colours coming out of the printer to what you see on screen. You will never get them to match
Hope that helps
Steve