Both, I go back and fowarth between the two. There's been times I mainly do traditional (never really coloring them though xD), but then there's times I'd do just traditional.
Right now I do my sketches on paper and then fix everything and color it digitally.~ (unless doing animation, original sketch for different actions is paper then the rest are digital xD)
I use both all the time, some people like it better on canvas or the way digital can pop if your good at it, this is a old one I did digital as a speed painting of carnage
http://imgur.com/zOsxRj2
most resent piece
Experimental-Traditional ink wash
There's been times I mainly do traditional (never really coloring them though xD), but then there's times I'd do just traditional.
Right now I do my sketches on paper and then fix everything and color it digitally.~ (unless doing animation, original sketch for different actions is paper then the rest are digital xD)
awesome.