Well, the lit buttons worked out very well on the road tonight

Yes, for me, too, as well. The brightness level of the "headlight-dimmed" buttons is perfect, no need to alter it from the defaults.

I had one incident shortly after startup on the way out of the garage, where it seemed to get confused about the line-state and the buttons were dimming incorrectly. I don't remember whether they were toggling between "off" and "dim" or if they were toggling between bright/dim but doing it backwards. But they were toggling wrong, I was sure of it, and had to correct it by rebooting (pull/insert player).

I have not been able to reproduce the toggling bug, and I tried. I don't know the conditions required to reproduce it, but it wasn't a big deal.