Since we are going in circles, I'll keep the circle unbroken:
"Would really like to hear from those who have done it, or have actively decided against doing it. I am particularly interested in hearing from those those who are maintaining a mostly stock truck appearance."
I have successfully gone from 6v to 12v and stayed with it - no problems (on a '54 pickup). It is a happy truck
I have successfully gone from 6v to 12v and back to 6v (my '54 Suburban). It is a very happy truck.
I will stay with 6v on my '54 pickup that will "all original type/looking equipment" (it is ready for final sheet-metal painting).
This truck might have a 6v original radio, or 12v look-alike radio (using a $50 6v to 12v converter for radios).
It will be a proud and happy truck.
If your grounds (everywhere) are good, and your generator/regulator are good and well-adjusted, 6v your lights will dim very little, if at all, at night.
If you change to 6v LED bulbs (available in 6v for all bulbs, except headlamps), they will be as bright as 12v bulbs.
If you need/want 12v devices, go 12 volt before buying 6v electricals.
Although, 6v to 12v voltage converters are available and are reliable (and, are relatively low-cost) for low-draw devices.
If you want a boomer sound system, or an AC system, change to 12v.
Considerations/concerns/complexities that are commonly posted/argued-over regarding 12v:
What 12 alternator/generator/voltage-regulator combination (and, wiring for that combination and components)?
What 12 distributor/coil/ignition set-up (and, wiring for that combination and components)?
Wiring/protecting your 6v fuel gauge and 6v ammeter gauge?
