Good question – my answer would be it all depends on what are the expectations. I think it is like the different forms of personal transportation – walk, run or drive a car. Each have rewards and difficulty. A brush works well with smaller areas, but is limited by how much paint it holds. A roller is preferred on larger areas like walls, much faster than what a brush could do. Production is always highest with the spray method, but is seldom done in occupied spaces. Brush and roll is preferred for inside work and is also done in conjunction with spraying of exterior surfaces. As far as appropriate or successful application of materials, it depends on the type of material and the substrate or surface type the material is being applied to. There are times when we use spray application combined with and immediately followed by ‘back-rolling’ the material to work it onto and at times into the surface.