After having used large format Epson's for nearly 10 years I wouldn't dream of going back, despite the fact that they FINALLY, only after being left behind in the dust in this regard, offered a unit that didn't require major flushing to change from a matte to a gloss media ! How kind of them. I'll never forgive them for all that wasted ink and time.
The gamut on the 9900 is excellent and the gray output very neutral. It is also very fast and sturdy. The two big things that would keep me away are: it being an ink hog, like all the Epsons, and ANY printer that requires you to STILL, after all these years have to do a friggin nozzle check before every rag paper print is a no go for me. That's absurd and there is no excuse for that. Both Canon and HP have software that constantly monitors the nozzles and ONLY cleans when absolutely necessary, not randomly and huge gulps of expensive pigment down to the wast tank, leading many people to surmise that this design is no accident. There are also a multitude of horror stories about the 9900 banding uncontrollably in both the black and cyan channels at these great speeds they are promoting. You might get lucky and buy one that actually works, but it seems to be a crap shoot right now. Meanwhile lots of Epson techs are going out of their minds trying to solve these banding dilemmas. This isn't an isolated situation and something to carefully look into before buying anything.
As to the Z3200 having an onboard spectro to make excellent profiles in 20 minutes or linearize in 5 minutes for monochrome, I think it is fantastic, hardly a disadvantage and I don't know how I lived without it. These Z machines do not require re profiling often at all. I can go at least a year without any drift on my standard media linearization ( which takes 5 minutes). My Z does a great job on all media. It can profile all kinds of canvas, strange fabrics, gloss fiber, or alternative uncoated media automatically, while I work on another job on another machine. The gloss enhancer coat for gloss media is excellent, with gloss differential non existent on most gloss papers. The speed is fine unless you are doing tons of production jobs, with massive print runs. One of the primary reasons I use a Z is because of the permanence that is twice what Ultrachome and Lucia exhibit. For my work longevity is important and more important than speed, but I realize I may be in the minority here. I used to have to spray Epson prints with toxic uv sprays to justify making portfolios or gallery work with them. I don't do a lot of volume and never pre press work. If I did I'd buy a Canon in a second. Neither the Canon or the Z printers waste ink the way all the modern Epsons do and they are workhorses. When a Z3100 cart says its empty, its empty. Heads are cheap and can be popped in in 5 minutes and they don't require that very often at all. Printing monochrome with the Z on gloss fiber media is a dream. The grays are not brown like Epson and no color inks need be used. If however they are used for monochrome work you know the hue added to the gray inks is going to fade at the same rate as the gray inks because they were designed to, which often isn't discussed in these comparisons. That is no small thing either. The Z sucks for sheet media at 8.5x11 size unless it is cut square on all edges, like out of a box. Sheet 11x14 and larger I never have an issue with,... but I use rolls for 90% of the work anyway.
Any machine you buy these days is going to produce excellent prints but for God's sake, keep it in warranty. They are just getting to complex to work on yourself.