I use a Canon MX300 and before that a 250 - simply wore out! They are real workhorses and I can't fault them on anything, but don't make the mistake that so many people do and leave them turned off all the time. In order to work properly they need to be turned on for at least an hour a day and that goes for any printer.
I switched to the MX300 simply to get the FAX feature which supplements the one in Windows although it sometimes forgets the settings and answers my phone when it shouldn't, however that is extremely rare.
I print quite a bit and can't fault the quality.
As far as functioning in 64-bit systems go, no problems here. It's important to not only install the latest driver
but also the Canon software associated with your model and it's readily available on Canpn's website.
Bought it for next to nothing, new, on eBay.