Well, I don't know how much money I spent doing all these ink / paper tests, but the effort is now paying off. I am able to turn out, at least at small sizes, very beautiful prints - and will be doing some re-scanning with the new 5400 before going to a larger size. I did a thorough cleaning of the printer yesterday - even using a q-tip to clean beneath the inkjet head, where I pulled out what looked like ink-soaked cat hair. I don't think that could have been good.
I'm not getting micro-banding anymore in any areas, and no graininess. I still don't like the "cold-toned" look from the ink -- but their are two adjustment curves, both on the warm side, that I like very much. I actually shaved for the first time in a week and cleaned the house up which means that this phase is nearly over.
I have an order to get out today - probably the last order with the old notecard workflow (Strathmore), and then I will begin making tests on the Red River notecard paper. Hopefully this will work out. It takes a lot of work to make less work for yourself.