I have always had excellent service from my Brother toner cartridges, black, cyan yellow and magenta. Trouble-free installation and timely reminder when a toner is getting low. Because of the Brother software, use of third party cartridges can be time consuming to get them to be accepted by the Brother equipment. Yes, they are expensive compared to third party prices, but this is offset by savings in time and meeting deadlines of the trouble-free installation and operation of the Brother cartridges.