^ 'tis true. I feel Mudbox's fairly advanced 3d painting tools as well as the standardized UI are the two main points that are keeping it in the market at all (what with Zbrush dominating in the sculpting area).
I respectfully disagree in terms of Mudbox. Mudbox is a great alternative for Bodypaint. True 3D painting and it has many of the Photoshop style brushes you mention, including the Stamp tool. You can even paint (and sculpt) in tiles.
The main problem I have with painting textures in mudbox is the difficulty the brushstrokes have with tracking the mesh. I think the issues might be related to scale from some digging around online, but everytime I try, I get really inconsistent results with the brushstrokes not following the surface. I have had occasions…