Dave and Deanwork,
Thanks for your replies. I don't have the space for a dedicated monochrome printer, otherwise, there are excellent solutions available for that, obviously. I am looking for the best all in one solution for monochrome and color needs. If the color gamut is at least better than the 7900, then I am probably happy going with the P10000, given the other (potential) advantages, real or imagined. The speed is nice, certainly, but not necessary in my world. Better heads are greatly important, and the ability for the heads to self-maintain without having to always put a sheet in the printer is a good thing. The slight loss of resolution is not something that I or my clients will ever see at any print size. The cost differential between P9000 and P10000 is not huge, and will be offset by half of an inkset. As long as the inks continue to be usable for a long time, which has always been the case, regardless of package labeling, I see no disadvantage.
I do not want a printer that has severely less gamut in color than the P9000, as when I do color, this is an important factor. With regard to monochrome, I would hope to see improvements in ABW, but no one has admitted to doing a test of this yet, on glossy media with PK ink.