For me, they each have a unique character. But you, having not spent much time in Brazil, may only see them as three Brazilian beach villages, one much the same as the others. IMO they are all worth a visit, and I am happy to go to all three. Barra Grande may be a bit more difficult to access, so remains quieter. Morro has a lively party scene in high season, but the recommended pousadas are in a bit more quiet area. Trancoso is known for the hippie atmosphere, and recently for a very chic scene.
For me, they each have a unique character. But you, having not spent much time in Brazil, may only see them as three Brazilian beach villages, one much the same as the others. IMO they are all worth a visit, and I am happy to go to all three. Barra Grande may be a bit more difficult to access, so remains quieter. Morro has a lively party scene in high season, but the recommended pousadas are in a bit more quiet area. Trancoso is known for the hippie atmosphere, and recently for a very chic scene.