1. They print in a fraction of the amount of time. If you need 30 cookies of something then an ink key will take a while while a laser can be in under a minute.
2. Ink jets drink ink
3. Generic toner is very cheap for brother and Canon printers
4. Each cartridge lasts longer
For B&W prints, I've been using Brother laser for years, they are cheap, fast, and last for ages.
Right now for color I'm using Lexmark machines and they cost over $200 for a set of toners.
For speed, I'm willing to sacrifice slightly, for a more economical solution. The ink jets now are not like the ink jets of old that did 1 page per min. They may not be as fast as laser, but they are still quite fast.
I'm looking at the Epson EcoTank ET-4850. Any thoughts?