The days of the impetuous clogs are gone for all brands. The technologies are different for each brand, and Epson being Piezo is quite different than Canon and HP thermal heads.
The most advanced checking, correction, protection is HP. Yet as an above poster stated, if turned off for long periods , you remove this guarantee of non clog status.
Both the 9180, 8850, and Z series use the same head types. Obviously the Z3100 has 6 bi-heads and different nozzles sizes for the GE, etc. They all have remapping routines to extend the temporary or permanently clogged nozzles. I doubt that this would be necessary on Piezo heads.
There are timed and counter set interval nozzle checks with adjusted intensity depending on printer model. The idea is the heads fire say three droplets at a park position over an optical or electrostatic sensor which determines the cells efficiency or lack of. This information verifies, then sets flags to be cleaned with various levels of the cap, wipe , and firing stages, the time to do so, and if out of spec a remap algorithm is instated.
A large number of cells can be remapped without any visible difference, even under a loupe.
This process when left in action uses little ink and guarantees a clog free print condition at all times for the HP system. Is it necessary for others? Probably not. Yet a guarantee that the printing condition is on par with the expected operating state along with Closed loop calibrations tells you that the repeatability no matter the operating conditions is met with unusually high repeatability.
What I like about the HP heads is the simplicity in remove and replace, and the access to manually cleaning the heads if needed. Epson when clogged are a pain to clean manually. I don't know on Canon if the two heads are easily serviced by hand or not. But they are user replaced.
