The recent advances in Fiber-based papers are wonderful, let me say that first and foremost. However, getting optimum results from these newcomers requires swapping out Matte Black for Photo Black in an Epson Pro 4800, 7800, 9800, etc. It's not that big a deal, however, until you consider the longevity of prints made using this ink/paper combination.
Just so we're clear here, is it the ink (photo vs matte) or the paper (rc vs matte/rag, etc.) that ultimately affects longevity of prints? I'd hate to have these new paper/ink combo prints fade on me after 20 years or so.