The only issue is Windows no longer recognizes it by default, so you have to manually install drivers off their website. And of course, Windows Update regularly breaks the install so I have to reinstall them. I don’t blame Canon for that though.
Getting new toner cartridges has been no problem as of yet, but I suspect the market is drying up by now because there were mostly off-brand ones available last time I had to get one.
There's no reason it needs to actually block the printing - it could simply pop up with a warning saying that the toner is low and attempt to print anyway.
I'm not sure about Brother, but I do know that some other printer cartridges contain an electronic counter in them that will declare them as "out of ink" after printing a certain amount of pages (even if there's plenty of ink left in the cartridge).
An amazing product. The UI is a touchscreen but it makes up for it by 70% of it being a giant blue button with “SCAN” on it :)
And so fast too.