I find traditional mediums far more challenging, at least if we're talking full blown illustration. Digital caters to my sporadic train of thought, and haphazard process. (general bad habits) Digital, once you've learned the software, allows you to focus entirely(mostly) on the creative aspects of an image without much concern for the process. Whereas traditional paint is much less forgiving.
However, for simple drawing and sketching I do favor the pencil. And if I were to delve more into 'fine art', then I would probably choose to work traditional.
My sincere apologies for replying to this so late!
Interesting. You make some good points there. There's no "undo" button in real life, so if a mistake is made on paper then that's it, unless it can be erased. The challenge is part of the appeal, though, I would think.
I'm with you in that I prefer sketching traditionally, although, lately, I've been doing a lot more of that digitally. As for full blown pieces, unless I'm in the mood for doing a very detailed, monochromatic composition on paper, I'll do those on the computer, particularly if color is involved. Coloring scares me, although I'm trying to get into the habit of working with it more....