I had the same experience, until I figured out what was going on in the driver. The printing resolution can vary from 300 to 1200 dpi, and the number of printhead passes can vary up to 16. If you have everything set to maximum quality, highest resolution, greatest detail etc. in the various driver pages, you end up printing at 1200 dpi with 16 passes. I'm guessing that this absurdly high level of resolution forces the printhead assembly to pause at the end of most passes to orient and locate itself with high precision, requiring multiple repositioning attempts of paper and printhead. I printed a 24x36" image on Hahnemuhle photo rag satin that took about 2 hours! Once I figured this out, I saw that more reasonable settings like 600 dpi yielded much faster print times with no difference in quality.
Thanks for the reply!
I am printing at the same detail level I always have. I select best quality and more passes but I do not check the 600dpi box. I send it 300 ppi files. I tried sending some 600ppi files at setting the res to 1200 and it definitely took longer but with no visible improvement. The printer only does 600 dpi so the 1200 setting must be some kind of psuedo-1200 dpi. I always assumed it prints at 600dpi whether or not it is checked.