Pen and paper worked great for me when I did everything at a desk (or carried a notebook with me) and I was always doing deep focus work. I went digital when I started being more mobile in my work and I had a lot of contexts where I needed to jot quick TODOs as I thought of them. Also, it's difficult to collaborate with my wife using paper.
The inbox mechanic for tasks works great, because I don't need to add all my task metadata right away. I can also annotate projects and contexts so I can say "what are my TODOs when I'm at home" or "what are my TODOs related to a person on my team". Now that I'm tracking over 20 things, it's necessary to stay organized
Strongly in the pen and paper camp, myself.
"I found some results on the web. I can show them to you again if you ask from your iPhone."