I would like to see cartridges designed ecologically - refillable perhaps, or at least designed to flow as much out as possible - and allowing you to override the "toner low" warning and keep printing even if it's almost dry.
Most are refillable if you follow an unofficial online guide. Beware that toner dust is really nasty stuff and gets everywhere, so however careful you are you'll still have clouds of toner dust escape and stick to every surface of your house inside and out... Top tip:. Never clean toner dust with warm water. It will stick and become permanent.
The best thing for cleanup is a 3M electronics vacuum which has a filter that will trap that stuff securely.