I do most of my writing on paper, but I don't think that is because of concentration (I think it's a deep paranoia that out there is someone who will take my work online as their own). I think it's good to write/read on paper from time to time. We absorb so much content these days, and much of it is really unavoidable on the internet with ads and stuff. Sometimes it's just nice to be able to do things at your own pace with no distractions.
That's impressive--writing on paper. When I left high school, we were just leaving the world of hand-written stuff. I had enough experience hand writing stuff, but in college, when I REALLY started writing quality stuff, I appreciated how flexible typing was. I don't do rough drafts anymore because the text is constantly evolving--it's fluid--until I finally decide to hit "attach" and off it goes to the professor or on to a blog or something. I LOVE the act of writing on a computer. But, still for eye-fatigue's sake, I print it out to proofread it.
I have always preferred typing because the motor issues stemming from my Asperger's makes my handwriting atrocious.
I'm in college too. We are required to produce all work typed on the computer. We usually just hand in the file. In that regard I'm kind of stuck, but I still write drafts because I found that if I typed them I would get lazy with my editing from draft to draft. Most of my handwriting is done for leisurely hobbies, but I also conform to the requirements of what writing and reading have become.