- Germany, southwest
If I understand your question, the benefit is mainly for holding thin wall components. Also they can be used for holding twist drills etc.
They have disadvantages over 3 jaw chucks however as if the scrolls get clogged with swarf it is a lot easier fighting your way to unwind 3 jaws than it is 6, also unless it is very accurate you will often not get a secure holding of the component on all jaws. When I had my 6 jaw I often just used 3 of the jaws, downside to that was the gripping face was narrower than a conventional 3 jaw.
I think YouTube has made them popular. Like you say, unless they're produced very very accurately to begin with and then kept in very good condition, you'll quickly find one jaw isn't clamping as hard as the others
I'm prepared to have the old lesson "you get what you pay for" reinforced.
I want to be able to clamp delicate workpieces without leaving marks on them.
I don't think I'll lose any money.