Re: Is it worth the extra $?
the second chuck looks better made and though shars sells chinese products they are known to sell decent stuff . Regardless they are both cheap compared to high quality chucks . Personally I'd go with a 4 jaw that has independent jaws and not self centering .
The rpm rating is irrelevant when being used on a rotary . Thats more of a balancing thing for high rpm work which doesn't apply in this situation
Re: Is it worth the extra $?
I bought the shars, just arrived, looks good except for an error on the back plate... almost looks like a machine crash
Fits the 1.5" square stock with plenty of base clearance and good clamping power.