I could refer you to one very unhappy guy who decided to try those ebay cartridges on a 7800, he though what the heck I'm just doing posters.
All was bliss for a couple weeks, but after a vacation it was missing nozzle and missing channel hell-on-earth and he finally just dumped the printer. Also, no canned profile will work well with those cartridges. Wonder how many 98xx series printers are on the market because of these carts.
If ink is still flowing in your printer, might be best to change to geniune carts while you're ahead of the game. I once in a while cheap-out here and there, but not on carts.