Digital BW, The Print

I am using an Epson 3880 for colour and B&W.  It takes 80ml cartridges which turn out to be fairly expensive per ml.  I have lowered  the cost by purchasing cartridges for the 7880 and transferring the ink into 3880 reloadables, but if I go to all that trouble, I might as well consider third party inks.

For B&W I am using a tweaked version of Epson's "Advanced Black and White".

I have been happy with MIS MK, PK, LK and LLK over a number of years, so I bulk load these.

I seem to recall that MIS colour inks are meaningfully less archival than Epson's but I cannot find verification for this online.  Certainly my experience has been that Epson's inks cause far fewer *clogs* than the MIS equivalents. . .

Is there any hard data indicating that a third party's colour inks are at least as long-lasting as Epson’s?

Any recommendations? 

Myron