Do you mean handpainting from scratch, or handpaint-style polypaint/AO/curvature baking? If it's the former, I don't see what's stopping you from achieving the same result as in photoshop, at least with MARI. I have only briefly used substance painter and wasn't impressed due to the 2048 max texture size and not being able…
I tend to do fairly realistic work and 3DCoat is one of my first stops as well. If I'm worried about UV distortion, I'll use it to lay down texture bases. It's also a nice tool for adding machine-precision lines without a bake. After I have my key features/masks down, I'll move over to Photoshop where I still do the bulk…