Is is 10 years old technology and very complex technology. I had a 5000 apart 5 years ago and in my opinion if your 5500 does not print within a day get rid of it, you will be hooked to it for months to come if you want to make it work. The inkset is Archival in all connotations :-) Very fade proof as it it is more or less "prefaded", in short, has no gamut. If it prints consider another inkset as it is a 6 channel model. Use color dyes or make it into a B&W quad printer then.
Edit: As far as I know there was never a 5000 or 5500 converted to B&W and I doubt QTR supports it or Paul Roark made curves for it. The minimum droplet size is at least 5 picoliter but it could be 9 as well. If you want an A3+ quad printer get a 1400 and check the information for the different B&W conversions. More fun, better prints and probably cheaper. Yes that 5500 has larger carts but two are split in two sections, each about 33 ML I guess so not that much larger. I have some 5000 parts stocked if you really think differently ........
Just my 2 cents.
Met vriendelijke groet, Ernsthttp://www.pigment-print.com/spectralplots/spectrumviz_1.htm
December 2012, 500+ inkjet media white spectral plots.