I have used Contrast and related paints (Vallejo Xpress and Army Painter Speedpaint) extensively on 6mm figures. My preference is a light grey primer (Tamiya) rather than white. The Xpress range is very good for late 19th and 20th Century uniforms. These types of paints make a noticeable difference to the time needed. For WW1 figures, you can get away without any highlights. I still like to add the acrylic highlights though. These make the figures really pop. Plus I photograph them with high-quality zoom lens and the highlights are more forgiving to the overall effect. I don't use washes at all now. 

Contrast-style paints have two important characteristics that are very different. The flow properties are significantly different. This is not surprising as the paints are designed to pool in recesses. This creates the darker contrasts around edges and raised elements on the figure. Takes a little bit of getting used to though compared to only ever working with acrylics previously. They are not the same as washes. There are minor variations in flow properties between some of the colours too. 

The flow properties relate to the medium. These paints draw up the bristles to the ferrule and accumulate there. With 6mm it is less of a problem as you need less paint for each section of the figure. I use separate brushes though from the ones I use for acrylics. You need a different solvent to clean the brushes thoroughly; water is not sufficient. Odourless turpentine works pretty well followed by The Masters brush cleaner to get into the area where the bristles pinch into the ferrule. 

Wouldn't be without them nowadays.

I have not painted Landsneckts but from what you have illustrated, Peter, I would not rely on contrast-style paints alone. For pre-camoflague uniforms, acrylic highlights are easy to add and will significantly enhance the visuals for mass figures.

Robert

The latest batch was done from a straight black undercoat, but I think I get the brighter colours in place.   They are definitely an easier task to paint than the pike: