I know when Zbrush first came out Projection Master was the go to tool for adding detail and color…But now with enhanced poly paint, spotlight and all the new sculpting tools…Is there really in practical reason to still be using Projection Master?
An advantage of Projection Master (and zapp link which works thru Projection master) is you have the option of painting high resolution images right to the texture set up for a low poly item, instead polypainting (vertex painting) a highly subdivided mesh and THEN transfering the image to a texture.
Edited to add picture of a cube with 8 active points and a 4000k texture textured with projection paint.
Another advantage of Projection Master is that with it you have access to the many 2D and 2.5D tools found in the Tool palette. You can even use 3D objects to paint color and/or depth onto your model.
If you really want to see how PM has a powerful place in today’s ZBrush toolbox, watch these movies: http://www.pixologic.com/zclassroom/homeroom/tutorial.php?lesson=sebastien