treadmill desk experience
I was intrigued by the idea when it first came out, and constructed one at my home. I made a large "C" shaped desk surface and set a treadmill in it. I found that getting used to the keyboard was not a problem and I was able to adjust the speed for various tasks. Reading was ok, typing was no change - with no back problems, and the only problem was accessing drawers - file drawers. I would turn it off for that. More and more, people are not using filing drawers in their desks so that may become less of a problem. I admit that I did not use it for drawing.
I did find it easy to adjust to, and the only real problem for me was a much larger space than the traditional desk. Other wise, Loved It! Suggest you vary the speed until you get used to it.