Hello, I got a very interesting answer on another forum from Ray, I give it to you here :
"The differences between dye and pigment inks has narrowed considerably in the last few years. It's not just ink technology that has improved, but also paper technology.
Pigment inks have inherently been more long lived, but have had their problems with colour gamut, which has been addressed through a greater number of inks.
Dye inks have inherently had a greater colour gamut, but have had issues with longevity, which has been addressed through better paper technology in swellable papers, as well as improved dyes.
Comparing my IPF5000 (pigment) and i9950 (dye) printers, there's not all that much difference in colour quality; however, B&W is much better with the IPF5000 because of the extra greys. That aside, and taking into account the latest Canon dye printers, I think that the differences have narrowed considerably.
The one big difference nowadays between pigment and dye prints is that pigment prints are pretty much waterproof; whereas, dye prints are definitely not. How either stand up to harsh sunlight conditions, I can't say at the moment, but for ordinary household conditions, I think both would be excellent.
The only other difference between pigment and dye based printers is that you have a greater range of papers to choose from for pigment printing. In a practical sense, this may not be an issue, as with my i9950, all I ever used was Ilford Galerie Classic Pearl. Most likely I'll never use more than two types of paper with the IPF5000."
Dinkyo