In my experience, the more transparent an act of writing is, the more productive it is. If the physical process demands great attention then it becomes a distraction from converting the thoughts into language. The writing processes that are the most familiar as well as efficient seem to me to be the best. I find both the oldest and newest methods problematic. For instance, the act of writing with pen and pencil I find to be too slow and laborious, as the brain can often perform faster than the hand. The newest methods involving portable electronic devices I also find difficult . The iPad, for instance, is great in its ability to always be available in any location, but I think the user interface is terrible. The on-screen keyboard is nearly unusable for intensive typing. Without any kind of tactile feedback I constantly have to look at what I'm typing and make corrections, and that distracts from my train of thought. But this technology is in its infancy and it will be interesting to see what advancements come in the next generations of slate PCs. For now, that leaves the middle ground of the venerable but boring keyboard. I find using a full-size, comfortable keyboard (along with a good monitor with plenty of on-screen real estate) to be the most efficient method. It provides just enough feedback for my subconscious to cope with the physical act of typing, while allowing my consciousness to remain on the task of reducing concepts into strings of words.
Of course, this way of thinking is based on the idea that the work is purely an intellectual property or product. As the electronic age accelerates, my experiences of a work or text in the post- iTunes world is becoming more and more based solely on content, and not on the physical artifact that was previously important. When the product of writing was limited to being only a physical object, the aesthetic value of the form was just as important as the content. Thinking about the physical process that Shakespeare might have gone through suggest that historic writers had to be an artisan in more ways than just using the word. Whether written for the public or for actors, the work had to project itself as a significant item. Losing this dimension of the writer may be the price we pay for the convenience of technology and the ever-present access to everything that exists in the electronic "cloud".