Check the sign outside the building. One time I went by and it just said Star Lord. Baby Groot was... temporarily unavailable. I went back later and Groot's name was no longer covered up on the sign, and he was available.
If it's just Star Lord, I wouldn't bother.
But if Baby Groot is there, do it. And if someone in your group is wearing a birthday button, and you like Guardians of the Galaxy 2, I would rate this as a "don't miss."