I keep asking myself, "why do you pursue this if using the printer/driver to manage colour delivers acceptable results?" And I answer myself...
1) because it's only acceptable with prints that don't push the gamut too much. Thankfully, I can ship my wedding and portrait prints, and some of my B&W prints. But there's no way my high saturation stuff is acceptable -- it turns turtle at the gamut edge and the hues change terribly.
2) because, even if it was acceptable all of the time -- that's not the way it's supposed to work. Rendering Intent is a very important decision and not one to be left to the printer. Colour spaces are too important to be left to the printer/driver. I can't resign myself to an sRGB workflow; that's totally unacceptable.
I see some of the colours coming out of the machine with each test print and I fall in love with it all over again. The blues are almost electric, and the pinks of some of my floral prints fairly scream off the paper -- but they are the wrong blues and the wrong pinks, because the printer's rendering intent is inappropriate and the colour space is wrong. I want to print those colours when my artwork indicates, and at no other time!
I like the printer mechanism, although I can see myself creating some sort of roll-feed cover with velcro and some canvas. I got too much dust in my studio to have media sitting out. But man, these colour issues are driving me batty. I got lectures to prepare for, prints to finalize, software to write, business plans to attend to, and, uh, that photography thing .... and I'm spending my time running the same set of six prints over and over again to see "is this any better? how about now?"
When this is over, a comp roll or two of media and some ink would be nice. But I'll never get the time back.