Digital BW, The Print

I'm confused, as usual.

It looks like PremierArt Printshield is being proposed as a
spray for papers like Epson Semi-Gloss to eliminate bronzing.
Sounds good.  You get a glossy print with good dmax and no
bronzing and a protective surface.  But I undersatnd this doesn't
work so well on matte papers like EEM, in fact lowering the dmax
a little.

But with EEM and the like, the Mayer rod with polyurethane seems
to give the same results.  And even though it's a little more
involved than the spray can, EEM is WAY cheaper than glossy papers.

So why use the RC paper with Printsheild approach ?

John