Not all of us send carbs off to a builder to get setup every time we change pipes.
I can bolt these up to various size motors and they will be good. They came off a 4cub, work flawless on my 10cub. And I know many more motor sizes I can bolt up and go. And tune "myself" within minutes with no guessing game, or sending off to my "builder". Thats how easy these are. Is that not worth it?
Like you always say Loco, whats another 100 for convienance, reliability, or preferance. But when it comes to something you dont understand, its a waste.