Regarding that, how good is the 'more passes' option at overcoming missing nozzles? If I even understand that option correctly that is... Does it detect missing nozzles somehow?
I'm not exactly sure Luc, so can't say much about that. I can say that as a rule, I print with "more passes" as standard operating procedure.
Here is what HP has to say about it:
If the printer has nozzle defects, you can still get perfect print quality results. The printer can automatically compensate for nozzle defects, so there is no need to replace the Printhead.
The method of improving Nozzle Defects is to:
1 Recover the Printheads, using the Front Panel Main Menu/Image Quality Maintenance/Clean Printheads option.
2 Reprint the Printhead Nozzles Test Plot to verify that the defective nozzles have been corrected.
3 If the problem continues, replace the defective Printhead.
You might take a look at this page on my website:
Z3200 Printhead InfoNotice that HP says not to replace the printheads. Then they to replace the printheads. It's pretty much like that. Don't, but then do.
Consider that each printhead manages 2 colors (or inks) and they cost less than the ink cartridges themselves. It is possible to clean them, yet given the fact that they are less expensive than the inks, when I see any issues cropping up, I try a quick fix, then if that doesn't work, I simply replace them. That's one of the great things about the Z3200ps - inexpensive replaceable print heads. Two for the price of one.
So anyway, I recommend reading that page, then doing a diagnostic image and checking to see that all the the printheads are doing well, and gain control over this process. In this regard, I believe this to be one of the most important aspects of maintaining quality of output.
Also, read the manual for discussions about banding. You might try "Advance Paper Calibration" (from the front panel). Sometimes this will fix certain banding issues. Between clogged nozzles and incorrect paper thickness issues, most of the banding should be able to be controlled, particularly if your files are processed correctly, which I expect they are given your discussion about tonality, dynamic range, etc.
Again, I just use "more passes, best quality" as a rule.