There’s no difference in shape, weight, specs etc. The only difference is that the groovy version has grooves on the catch zone on the yoyo, and the finish is smooth (no grooves) on the smooth version. I’m not sure how, if it all, it affects play.
they’re not better, they’re just different.
As of right now, they’re not for sale separately. Werrd is working on selling some part stuff though. Like jimmy hats, split d rims, etc.
The only place to get them is either werrd sometimes sells them at contests where they have a booth (I was able to buy two pairs at worlds) or from a private party. Not sure, but you might also be able to contact werrd about it.
The beefcake is made perfectly for the yoyo. The bearing seat is very deep so that 2 bearings will make the gap just as wide as 1 bearing will. The beefcake uses the curved edges of the bearing to make a notch that the string sits in. Plus, it’s kinda cool haha