I think Panascape's reasoning is very sound - if you are a photographer who's used to Epson or Canon prints, and you require absolute precision in the colour of your prints, then the HP is not (yet) for you.
If you're like me and are happy with prints that aren't 100% accurate but which have predictable treatment of out of gamut colours, then you can certainly live with the printer.
Zebra striping is not an issue if you specify the correct paper weight initially. Unlike some initial reports, the treatment of out of gamut colours (especially reds) is just fine - they get mapped to a very believable shade.
I'm providing this comment as a bit of devil's advocate for those people who are considering buying the printer who are looking for a positive comment. So there it is - don't buy the printer if you require absolute colour accuracy and the same gamut as the Epson. Otherwise, go ahead - you won't be disappointed.
It's also my belief that gamut will increase as further firmware development is made. I am irritated that HP would release what amounts to a beta product on the market like this. But that being said, they seem to be taking the feedback seriously and working on it.
As for the comment on why the initial firmware release mainly covered the HP papers - I'm sure that the rest of the paper types will be covered in the next release, and I'd rather have some imrovement now in some papers than have to wait for everything.
Many compliments to Peter, Robert and Christoper for their excellent and balanced comments. I certainly won't flame you!
My previous point was simple -- Robert and Christoper ran simple tests, by printing standard test images, on HP and Epson, and compared the results. The HP engineers should have already done just that, and not released the printer for sale in light of the results. I was denounced as "hysterical" for making that point.
I entirely agree with Peter on his final point. We need a new firmware release first, even if it is only for HP papers. Then they can follow up with a firmware release that includes "photo papers" and "fine art papers" that are not HP products.
Final comment. Corporations are corporations. They are driven by the bottom line. They release flawed products prematurely to try to get a return on investment. To be surprised by this is the equivalent of Casablanca -- that we are shocked! shocked! that HP would do that. It is naive to simply defend HP as some great company, and ignore the record of HP with regard to this printer.
Nor should we surprised, down the road, if they don't commit the resources to fix the problems without pressure from this forum. They didn't do it the first time, and won't do it now left to their own devices. The balanced comments from Peter, Christoper and Robert are perfect. The message to HP is that professionals who demand accurate color should not purchase this printer at this time if that is what they require.
That applies the necessary pressure on HP to correct these problems so that the Z3100 moves from a printer for advanced amateurs to a printer for professonals. After all, few advanced amateurs will spend $4100 or $6300 on a printer.
HP either turns this into a printer for pros, or they are not likely to sell enough to recover their investment, let alone take market share from Epson.