Gosh, I'm so glad Jinbei is there. Luffy have gotten quite smarter than before. Maybe Ace's death affect him so much that he managed to think about pro and cons.
If you analyse his behavior during the last arcs Luffy is still rather reckless and impulsive, but he listens when people he trusts warn him about the importance of considering dangers and circumstances... I don't think he's smarter than before but rather that he has learn when/how to listen to other people's advises... I believe the main reason he is considering the possibility of joining forces with Bage Capone (that is by far the best oportunity right now, even when he can't really trust him) is because this is Jinbei's idea. Luffy has Jinbei in high esteem, he trusts his advise, and Jinbei's influence has always help Luffy to act more mature... It's like if Rayleigh was his marcial arts/haKi teacher who teachs him how to fight while Jinbei is his advisor and how to be a leader teacher.
"Do you like Big Mom?"
"WE HATE HER!" That got me ROFL so hard.