Digital BW, The Print

Joel, I have been using nearly the same set up, but with a 9600, for
over a year. I have had occassional problems with ink delivery,
particularly in the beginning, but now the printer tends to perform
for weeks at a time with only the occassional cleaning required. Then
it will be picky for a few days.
I don't want to suggest you should stick with a system that has cost
you so much grief. But just a couple of comments-
Banding is not a SP problem, it's a problem with any partitioned quad
system. Any nozzle drop out, any misalignment, or paper feed
inacuracey will result in banding. Any solution using UCs, where
multiple inks are used throughout the scale, will be less sensitive. I
can't imagine any fewer banding problems with IP in quad mode than SP,
however IPs UC B&W method will probably band less.
Not sure what experiences you have had that suggest IPs dither better
than SPs either. I'd be interested in more info.
I agree with your assesment of the acceptability of UC B&Ws in the
fine art realm, though people are doing it anyway.
I would suggest a higher humidity then Larry suggested as well, and I
usually clean and soak the capping station a few times a week. Also, I
found wiping the bottom of the head over windexed paper towel was
needed more often than I anticipated.
However, over the years I've seen people like yourself caught in a
cycle of problems with any number of systems, and at a certain point
it does seem wise to walk away. I'm very reluctant to suggest that you
 stick it out.
I don't think there's any system that really compares, frankly. I'm
wondering, since you have the RIP and like the prints, if it would be
worth looking into one of the other supported printers, even outside
the Epson family. Perhaps for the bigger investment, a more reliable
ink delivery and robust performance throughout would result.
Might be worth looking into. Steve's suggestion about the 7000s and
9000s is good to, I know several users that seem to be problem free.
But you won't have 7 inks, and will have to alter your hue/split
toning set up in SP. Most frustrating, problem free x600 users, x600
users with problems, and no viable explanation. There was no mention
of dampers in your email, flushing r replacing.
Wish I had something productive to offer.
Tyler