I routinely use all sorts of inks in Epson printers. Their piezo heads are wonderfully tolerant of the differences that may occur among the inks (unlike thermal heads). I simply will not buy an Epson for which there are not good empty, refillable cartridges.
Because I specialize in black and white photography, I use dedicated B&W inksets in many of those printers. See, for example
http://www.paulroark.com/BW-Info/Eboni-Variable-Tone.pdf (though I now standardize on the stronger toner as described in
http://www.paulroark.com/BW-Info/3880-Eboni-Variable-Tone.pdf). The "Eboni" variable tone B&W inksets are for matte only and the most economical due to the generic dilution base that is or can be used for making it. For glossy (and matte) B&W, this is the current approach I use:
http://www.paulroark.com/BW-Info/Glossy-Carbon-Variable-Tone.pdf .
For color, I am currently using bulk Epson/Noritsu color dyes. I have reverse engineered a dilution base so that the dyes can be used in any Epson printer -- great color, no bronzing or gloss differential. I used this color dye in an Epson 4000 for years with outstanding results, but, of course, even the best dyes are not in the archival league with OEM color pigments.
MIS Associates -- aka, InkSupply.com -- has commercialized some of my open source formulas, including the generic dilution bases. See
https://www.inksupply.com/roarkslab.cfm. I receive no royalties and have no ties to MIS. I allow them to use my name only if they have only those things on that page that I've formulated or tested as being compatible with my workflows. The point is to get as much competition as possible to the field. The formulas for the generic bases are listed right be the products as well as on my web pages.
While I use third part carbon for B&W (carbon is by far the most lightfast pigment), I "tone" or cool this naturally warm ink with a light blue toner that is composed of Canon color pigments. For the most lightfast color, stay with the OEMs. The resulting neutral B&W prints beat the silver print in my fade testing. (But, honestly, most of this is just the paper base. Silver and carbon are both very solid.)
The point is that the Epson printers are wonderfully flexible machines. It's too bad the enforcement of our US antitrust laws has been so weak in this country as to, as a practical matter, allow the printer companies to "tie" the ink sales to the printer sales. Europe is more inclined to enforce the laws against such tying. (I am a former antitrust law enforcer.)
The bottom line for me is that I have no interest in any Epson printer that locks me out of the wonderful world of open inksets. On the other hand, my 7800, 9800, 1430, and 1100 hum away with totally reliable B&W and great Noritsu (Epson Claria) inks in them.
Paul
www.PaulRoark.com