Agrax vs AP Strong Tone vs paint wash

I've had some problems with my Army Painter Strong Tone wash. It gave my miniature a glossy finish and left beige frosting in the recesses. I asked around and was advised to shake my wash bottle well before washing. It was good advice and it worked – to a point; there was still some gloss and frosting left. So I started thinking of switching to another brand. Pictured below: frosting But first, I wanted to check how different brands work out. I took four miniatures for my RRT infantry unit. One was washed with Citadel Agrax Earthshade (A), one with Army Painter Strong Tone (ST; I mean the acrylic wash in a dropper bottle, not the Quickshade dip), one with thinned down paints (P, the paints used were VMC beige brown mixed with VGC black), and for comparison I left one not washed (NW). I sprayed the minis black, then white. I painted the uniforms in two very thin coats of my olive drab mix. The armour was done with a number of thin coats (maybe they count as glazes) using...