Step-by-step instructions in the box make it easy to refill the tank. First time it took me less than five minutes. It's well designed to ensure the toner goes into the tank and no where else. I save so much $$$ with the laser tank printer. I'm thrilled with it. And, it eliminates toner cartridge waste.
The number one reason to use is the cost compared to "cartridges." The printer may cost a little more but in the long run this is much more cost effective!!!