Looks good but slow, missing features & poor Mac support
We have had this printer for about 8 months. Although the specs look good and functionality is great for the size of machine, it is missing some key features, especially around paper handling (cannot use custom size in drawers, no option to automatically use A4 for a US LTR request) the annoying alarm beeps will begin to haunt you!
We have a Mac only peer-to-peer environment and this printer does not support Bonjour, Mac drivers from Canon take a while (months) to keep up with the OS and we have 30 identical machines with the latest driver where over 10% cannot print, driver simply shows "Error -170". Canon support is fine if you've just forgotten to plug it in or similar, but after that they seem to lose interest.
Reliability: One fuser failure otherwise good.
The issue of printers and all-in-ones not automatically switching to A4 from US Letter is a pain in the derriere for us as well, and we can't see it being resolved any time soon as it's been around for years. It's not limited to Canon, in fact we get the exact same problems on our HP all-in-ones and as we've heard from so many customers, it's a problem across pretty much all manufacturers.
We'll pass your feedback on to our account manager at Canon regarding the OS issues and the lack of support you seem to be getting from their Tech Support team.