Oddly, I have not found that quite true. I tried holding down to only movements, and besides being much slower, the same distortions crept in (slower, perhaps, but still there). Related to this, I recently was working on an apartment building in scale and set up the workspace for 1-meter scale and a 50-meter working box. The camera, however, seemed to be still locked at figure scale; an infinate amount of scrolling to get it around this large structure, and the reference position quite unusable. When I have the time I'm going to experiment with different settings for the working box and find out what the relationship is with the camera. One thing I like very much about the last update to 3, tho, is that if you have a split screen, each window "remembers" how you had the ortho cameras set. By going to the same window you get the same camera setting back, even if you moved it in another window.