The addition of Lm, Lc and Lk would only mean that colours are reproduced with a less obvious dot pattern/grain, and the absence of them does not change the overall colour reproduction (colours are not supposed to shift in lightness, hue or saturation). The dual drop tech is supposed to help out with that. I've seen some samples but I do not have a Z3200 to compare against. I'm assuming when you say they are a close match in this context, you are referring to the dot pattern, smoothness/graininess and highlight detail?
I never quite understood what HP means by being able to "mix" colours/inks at a pixel level. Is that not what Epsons and Canons do? I watched the marketing video and it makes me even more puzzled. The technology promises greater detail, deeper colour and smoother transitions - I'm sorry, I don't want deeper colours than my original, I want as faithful a reproduction as possible. If they mean deeper colours as in more total gamut is realised with the same inks, that would be quite remarkable indeed and it could only possibly affect colours that require mixing of inks, not pure hues. However, you have already mentioned broadly similar gamut and detail between the Z9+ and Z3200, so it seems that whatever HP Pixel Control is doing, isn't making much of a difference at all. I've also not ever had a problem printing smooth transitions on Canon or Epson printers, and I believe the Z3200 was excellent in this regard too.
HP has a relatively sophisticated process in how the printer thermally heats the ink, mixes the colors then sprays them out of larger and smaller orifices in the printheads. If you look at page 6 of the service manual, you'll see "Theory of Operation" schematics which will explain it much better than I can. (
https://shared.swissparts.ch/manuals/HP/Plotter/HP%20Designjet%20T1700,T1708,Z9,Z6%20Service%20Manual.pdf )
Aside from marketing hype ( and remember, HP is definitely marketing these printers to market segments other than fine art photography ) and the poster making market is an important segment to them. They claim that posters benefit equally as fine art prints, but definitely discuss uses of substrates affecting longevity in their literature. Putting market hype and claims aside, real world experience tells (and will tell) the story. Again, it takes time to thoroughly evaluate these things.
I mentioned synthetic gradients only because you can make them noise-free and essentially perfect, so any inperfection in the print must be introduced by the printing process and is thus the maximal stress test for smoothness. If anything, it would help to show off how much better HP Pixel Control is helping.
Happy that it's working out for you. During a HP Z9+ demonstration where I was present in person, a roll of HP Super Heavyweight Plus Matte paper was loaded and head strikes occurred at the very beginning of the roll. It was not towards the end of the roll. When I pointed it out, I was told that this is a known problem and the media needs to be advanced a bit to avoid this issue. The worst problems I've ever faced with these types of printers are paper handling related. Maybe I'm just more unlucky than most, but then again this demo printer wasn't mine :-)
Yeah, IMO demonstrations really don't tell the real story. For the most part, the operators doing the demos aren't specifically trained in serious work with the printers, again, IMO. As I said, there is and has been a particular culture of working with the Z Series printers that consists of tips, tricks, workarounds and fixes that studio photographers and professional printers develop to avoid mistakes that beginners or mediocre operators make. But beyond that, "There’s no perfect printer out there, IMHO. One has to deal with workarounds with any of them. I can deal with paper feed issues. Clogged nozzles, wasted man hours trying to get printers back on line - That’s a PITA"
So there's no comparing apples to apples or oranges to oranges with Canon V. Epson V. HP. The HP Z printers are in a league of their own. And with it comes amazing technology that squeezes out more blood from the stone IMO, but each of us have our favorites among the printers available. And let's face it, they're all really very good. And they all have issues.
Since I have made a fairly exhaustive study of the Z3200 series printers from many aspects of the printer mechanics, theory of operation, and usage since the Z3100, and for the last several years working with Mark McCormick Goodhart to create extended patch targets, the user level for that machine is vastly different from the normal user. Several of us have chosen to invest the time and resources to experiment with the printers to see just what they are fully capable of, and it has been rewarding. As I come to know the Z9+, this sort of "tinkering" with the printer seems also possible, but at this point, the one hurdle is the limited access spectrophotometer, which if unleashed again, as it was in the Z3200's, this printer would be unquestionably the no-brainer choice for a good many printers looking to push their work just that much further, without spending excessively on automated spectrophotometers that would otherwise be unjustified for occasional use. Even with the limited 464 patch target and resultant straightforward profile making capabilities, resident in the machine for all to use, just as it is, makes this printer heads and shoulders above the rest, particularly for those who prefer to use, test and experiment with various papers, considering that like the Z3200ps, it comes as standard equipment providing quick, easy, more than adequate custom profiles arranged carefully, afterwards, for that matter. This is not the case with Canon and Epson as we know.
The Z9+ has essentially a much improved robotic (automated) high-speed spectrophotometer replete with amazing speed and accuracy. With the new reference files Mark MHMG and I have been working on and John Dean and I have been testing (along with Mark McCormick of course), on the Z3200ps printers, that research, has in turn applied to the Z9+ series, particularly in concert with the Z3200ps embedded spectrophotometer and color center that creates Tiff files to be printed by any other printer, then scanned by the Z3200ps at a much lower speed, but there is hope HP will once again institute the extended profile capabilities of the spectrophotometer in the speedy Z9+, even if as yet another accessory that can be purchased as before in the Z3100 and Z3200 printers.
There's a lot to like and even love about this new Z9+ printer. There's some things to be frustrated with. Hopefully many of those things will evolve in coming iterations.
-Mark