I find the Lexmark laser jet to print great (BUT YOU NEED TO SET DEFAULTS IN THE PRINTER SETUP TO GET IT TO PRINT WELL), but these cartridges do not last long. I would be surprised if I get three quarters of a 500 page ream (IF THAT) from these expensive cartridges. So, I've learned to print most things on my Epson Echotank printer (Over 23K pages on same head!!) and only Customer Facing documents with the Lexmark.
Anyway, with these cartridges, they work very well; they just do not seem to last very long.