This is very like the difference between analog wristwatch or a clock with hands, and applies to anything that displays numbers zipping by. Most times, one does not need the exact time (say) in numbers. You want to see how much, proportionally, there is left up to, or after, some important point. Actually reading a set of numbers, and doing the mental addition or subtraction is a 2-stage think, whereas a single glance at a dial, (or clock face) of any kind lets you know in milliseconds the "which way", and the "how far". I don't get on well with the F1-style digital speed display option on my car either, but fortunately, the menus let me choose a dial display as well.
I don't have a Trav-a-Dial, but I am sure able to identify with why you like it. The answer is to have both features, and you are right that it is completely possible to to display a position analog value along with the digital number.
With electronic kit I use, the digital readout meters have the same issue, and my multimeter features a horizontal "bar graph" as well as the digits, to help in adjusting for maximums, or minimums. They in effect emulate the movement of a analog meter needle using a line of little lit up dots.
It happens everywhere! Look at the dancing VU-meter displays for audio consoles, specially programmed to hit a peak, delay there to aid our senses, and then fall back in a damped fashion like the pointers on old-school analog meters. I can't imagine changing audio levels displayed as changing numbers would be viable, but our brains can assess a proportional analog value in an instant.
I love (and need) having the number display and precision of a DRO, but only when it is stopped. When it's on the move, you have to pay attention to approach a position without overshoot. This is something much better done by a dial displaying travel.
