Mine's a "waster", in that it'll tell me to replace the cartridge when it's still a quarter of the way full. I'm more concerned with the color cartridge, and with monitoring each of the C,Y, and M levels. It's much easier to tell when the black cartridge needs immediate replacing.

I've found Canon printers to be less obnoxious than HP or Epson about ink wasting. My Canons will run the ink cartridges right down to "won't feed". But all of them do the same thing: refuse to print if any of the cartridges is depleted. Inkjet engines just aren't made to run correctly under those conditions. Because the manufacturers are in the business of giving away the printers to sell the overpriced inks, this situation is, sadly, just fine with them. And since businesses buy few inkjets (if it's worth money to have a printer, you'll have a laser model), consumers don't have enough leverage to get a better deal.