If prints are for exhibition it is important to judge the glossyness of the final print/paper behind the exhibition glass. There is no point having a paper that looks great on your desk - but once behind glass looks too reflective.
Alex
Good (some say bad) news is the K3 Inkset on any substrate can't make anything near as smooth and shiny as a hi gloss ciba or fuji crystal archive chromogenic print. These so-called "glossy fine art" papers are really more a semi-gloss, which look great under glass in exhibition conditions. I find the coating on the Silver Rag and the Fibra print both to eliminate "gloss differential" the annoying inkjet effect where the substrate is glossier than the ink, and the final print therefore not havinga continuous smooth surface.
The whole gloss/matt terminology has been a bit crazy of late, exacerbated by manufacturers that want to sell you the likes of "matt surfaced gloss paper", which I think means a stippled/lustre/low reflectivity surface (the matt part) on a resin-coated (as opposed to raw paper/fine art) base (their "gloss" part).
And yes, Alex is spot on, if you're that keen as it seems you are, always assess the final print under display conditions... not just under glass but under similar light that you have in the display space.
And while they seem to be dry off the printer, K3 prints need a couple of days to really cure, so if you have the time, do a batch of test prints, let them sit, then assess them and adjust and re-test.
Also, while I am confident with my monitor/soft proof/output loop - it gets me very close, often spot on - nothing is as accurate as a test print, just like those good ol' days.
Have fun, and if you're doing a bunch of prints, don't forget to budget in a couple of throw-aways due to paper irregularities etc its the nature of fine art, and particularly cotton rag papers. While its not my taste personally, some folks in art circles like the "flaws" as it makes each print an individual piece.
and don't sit up too late, assessing prints through half-closed eyes ain't that successful.