A:AnswerI looked at both and settled in the Galaxy Watch 5 and have zero regrets. I love the ability to change watch faces, the features and compatible apps, and the battery life.
A:AnswerI believe this is a 20mm wide band so if your Galaxy 3 has a 20mm band then it should fit this watch. From what I saw on Amazon some of the Galaxy 3 watches had 22mm wide bands so just be sure of the width of yours.