But we are no fighter pilots who accelerate from naught to Mach 2 in mere seconds. For those, a round steam gauge might be more useful. We are airline pilots who simply fly the bugged speed. That's why I'm still not convinced that round steam gauges are safer in our type of flying.
Furthermore, the digital speed tape provides a very clear picture, more intuitive than a steam dial can ever achieve. At a glance you know your minimum, maximum, bug and actual speed. It's all there in a neat package. There is no more mental processing required other than to follow the bug and avoid the red and yellow. Again, you are not flying digits, you match up the speed index with the bug...