Most successful claw design?

[Chris is me]

Rollers are great, given infinite weight, motors, and support. But that's rarely the case in robotic design.

The advantages of other claws aren't based on competitiveness, but on resources.

[CalTran]

I think clamp claws work well. Our team is great with hitting a tube and grabbing it on the go. Our claw is a bottom plate with a pneumatic clamp at the top. Then we have something akin to a "tooth" to keep the tube in.

I also like how Team 1986, Team Titanium, has their manipulator.

[artdutra04]

I may be biased but narrow roller claws work like a charm. They very quickly acquire tubes, very quickly score tubes, and depending on their implementation can easily hold tubes from "impossible" positions, like the very corner of triangles or squares.