By my reckoning, your linked youtube video shows "just" a capacitor and a bridge-rectifier (not a voltage regulator).
To each his own but I think the photo (clipped from your video link) is RIDiCULOUSLY bright! GRJ's module allows brightness control...amongst many other benefits.
Full disclosure, I have absolutely no business relationship to GRJ's goings ons and arguably we disagree here on OGR more than we agree! Also, you get support from fellow OGR participants with his module which is absolutely priceless IMHO.
Stan, I suspect he's also driving the LED's way past their rated 12VDC spec. He has a bridge rectifier and a pretty large 4700uf cap, so I'm guessing unless the voltage on the tracks is in the 9-10 VAC range, the output DC is way over 12V.