I looked at the other thread which I assume is this:
https://ogrforum.com/t...-o-decals-led-strips
Here are 3 additional differences more to do with assembly/installation than the "electronic" differences of AC vs. DC
1. Soldering. As I recall when GRJ's board were designed, one consideration was for a no-soldering-required installation. The "kit" version of his boards allows this. As shown in the other thread, soldering was used.
2. Connectors. GRJ's kits come with connectors so that you can separate the shell from the chassis. From what I can tell in the other thread, the shell and chassis are permanently tethered by whatever the length of wiring supplied. I suppose it's arguable that one would never have to open the passenger car again with long-life LEDs but it is nevertheless a difference. For example, if you later choose to go back to detail the interior, add additional LEDs for markers, vestibules, etc. then there is a benefit to completely separating the chassis from the shell.
3. GRJ's kits appear to use fatter wire gauge and what appears to be stranded wiring (?). The bare AC-strips appear to use very thin gauge "magnet" wire which is solid enamel coated wire. The thin magnet wire is probably easier to disguise or hide but from my experience it can be difficult to work with if you need to attach connectors, make splices, whatever. That's just my opinion of course.
And as alluded to in 2, if you indeed go back in to add LEDs for more than basic interior lighting, it's much easier to start with the regulated DC provided by GRJ's board than with "raw" AC track voltage. Again, that's my opinion.
Gosh. You'd think I was a paid shill for GRJ's boards! Not! Never met the guy!