It depends on your play style.

I am bias. I want Kurama.

Kurama actually can pops off every round if your standard does 10 hits

He doesn't require setup like Madara, where he needs 60 CP to use his mystery.

Kurama slot 1, pairs with Roshi easily trigger Roshi's chase. Ignite and immobile.

Added: for my personal Kurama is easier to build a team than Madara.

But if you already have someone like Itachi and Sasuke Susano you might as well want Madara.

Madara pairs with Susano Sasuke, your enemy would have hard time to take down another, where one immune to tai and the other immune to nin.