See the test on the right -- click for a larger view. The center is an overlaid piece of this new matte media, and the underlayer (outer edge) is the watercolor paper I had been printing on before, Somerset Velvet watercolor paper. Both were printed using this printer, so the inks and resolution are identical.
As you can see, the new stuff is SO choice. I never thought I'd find something I liked better than the watercolor paper, but... yay. :D By the way, I think those vertical lines on the new paper are a scanning or resizing artifact... I don't see them on the print itself.