I've had much better luck applying the fumed silica wet rather than dry. I even went so far as to buy a cheap blender to mix it. But otherwise, my experience with it is on a par with what Mr. Klain says - it produces a notable boost to Dmax and overall contrast increase. And applying it wet doesn't add THAT much time to the coating process. I find it dries to a coatable surface within minutes.
How do you mix it? Quantities? Suggestions? I am thinking one could do up several sheets for future coating.
Thanks for your observations.
"There are a great many things I am in doubt about at the moment, and I should consider myself favoured if you would kindly enlighten me. Signed, Doubtful, off to Canada." (BJP 1914).