I have extensive experience using two printers from Canon - First is MF4320 (in office), which is a monochrome duplex scanner/printer/copier; while the second one is Canon LBP 5050 (at home). Both are good or bad in their own ways. MF4320 is a no-nonsense printer that will never fail you no matter how many prints you plan. With this printer, I have no worries even if hundreds of prints are requried. It is fast on both printing as well as scanning fronts (scanning speed is awesome in monochrome mode); though scanning quality is certainly not among the best. But it does most of the office work well.
On the other hand, LBP5050 is a perfectionist. I had bought it in 2011 for printing my PhD dissertation and its quality of graphics was simply superb. No printer in market could match the quality. However, perfection requires patience - and quite lots of it when it comes to LBP5050. I have always used original toners (the set of CMYK toners costs almost as much as the printer itself!); and it still spends good deal of time in correcting that minor, un-perceivable "error" in calibration, adjustment or simply for cooling-down if not kept in an AC environment during summer season. It is certainly not suitable for heavy-duty application; though it has got me rid of the ink-drying problem that I used to face with HP840C deskjet at home, which too was a respectable and high quality printer of its times.
A couple of days back, the LBP5050 stopped printing in black; the problem persisted even after replacing the cartridge - seems as there is some electronic problem with the printer, as it is producing very faint impression of the document in black, while the Colour printing is working fine (except the black component in CMYK). Planning to take it to service centre tomorrow and will be able to share further experiences afterwards.
