The watch comparison is flawed in my opinion. On a digital speed tape you still do not look at digits but at the speed bug. So at a glance you know wether you are a few knots fast or slow in the same way as glancing at an analog watch.
You fly the bug, not a digit so the thought process stays the same wether you have a dial or a tape in front of you. In the 737-300 we had both, a steam gauge dial and a digital speed tape. I preferred the tape.