So, what's really changed/improved since BCI-6 carts?

[stratman]

Maybe Canon has implemented a better algorithm for keeping the print head primed for your printer. Maybe it will count the time the ink cartridge is removed. if it is pulled and put back in immediately it does not need to prime? If your pull one out longer then it will prime? Just my guess. My observation on ip4700 is that it will prime always whenever a cartridge is pulled and put back in. Although it is for a good cause it is annoying. The priming happens eight before it prints. The printer will memorize that a cartridge has been disturbed.

I have had similar thoughts about if time out of the print head makes a difference, but i have not paid close enough attention to make a reasoned guess. I was going to write something similar in my reply to your print head alignment questions.

I am not sure my printer, and from the sound of it others printers as well, follows the maintenance cycles as dictated in the service manual. It could be there are other routines programmed that are not published, including one that accounts for the age and/or usage of the printer. It could be that in bypassing the empty cartridge warning or using a reset chipped cartridge somehow alters the pathway selected on Canon's algorithm. It could be that Canon's programming is not robust and errs in execution.

People have posted that maintenance cycles increased after they overrode the empty ink warning. IIRC, someone with two IP4700's said there was no difference between printers - one having been overridden and the other not. Maybe it was a firmware change between the two printers that caused the difference.

It is a confusing picture, one we do not know enough about.