I have plenty of yoyos as smooth as my Battosai. Skywalker, Equilateral, Phenom, Anglam, my OD’s, my CLYW’s, my G-Squared, my Royale… KLR, Essence, VOID, Superstar. TFL, 4XL, Solaris… too many.
Price, size, etc, didn’t matter. The yoyos speak for themselves.
A good, clean bearing and a strong, straight throw will do amazing things for the smoothness of a yoyo spinning.
I find unless the vibe distracts from playability, I don’t worry about it too much. Fun is more important than smooth. Plus, with a little vibe, I can feel it on the string better.
there is no smoothest yoyo because even yoyos of the same model vary slightly in “vibyness”
hear is a list of companies that are know for making smooth yoyos: onedrop, spyy, general yo (forgive me if I forgot one.)
hear is a list of dead smooth yoyos I have tried: burnside, code 2, capless, code 1, pro, yyj solid spin axle, spinfaxtor x, KLR, genesis, and the list goes on
Important note: a onedrop 10ball or a twisted trifecta can make a yoyo with minor vibe dead smooth! I prefer the trifecta for the string centering. IMO the OD 10ball is 0.00001% smoother on every tenth throw.