I would keep saving. Ao is gonna pretty much fade away faster than you can say "But, why tho?"

Between the two Jinchuriki Super Rares, I have to say my favorite is Han. He can dissolve shields and buffs in Round 1 (Tho watch out because it will also dissolve yours) and then he can attack with his mystery in a future round. Sort of like Temari. Han heals himself every round, and is immune to knockdown, lowfloat, highfloat etc.

But incase you were wondering about Roshi, He can destroy barriers with his mystery. And he is immune to debuffs like Immobile, chaos, etc. He hits pretty hard, and c*so take a hit. He also heals himself every round.

You can see why I like Han more than Roshi, but in a perfect world I would say try to have both.

Han is the best choice I think. I mean if you ask anyone if they would rather have Han or Ao, the answer is simple. I know it might seem harder now to have to wait, but once the time comes you will be so very glad that you did. Trust me.