I'm the guy that says it's hard to find someone who can improve enough on factory paint (nowadays at least) that's worth how much money custom painters charge. The biggest problem I have is when someone makes a custom head, casts it in cheap resin or plastic which is either gray or white, then another customizer does an entire paintjob on the head. It almost inevitably ends up looking like a toy. If the custom is cast in translucent resin and the painter can forego the flesh tone coat and go straight for the details, it's a much better process. Unfortunately, even then you only have a few people that can legitimately pull off factory-level paints. And by that I mean the paints we get now from HT. Almost any customizer can improve on what we got when BRJ came out.
[Edit] I have no response to this that doesn't make me sound like a ____.
P.S. I think the factory BR paint is great.