It's such a refreshing One Piece experience to me. After being stuck on Onigashima for 2 years with battles after battles, I get to enjoy a fun music-centered movie that has a lot of heart in it with minimal action. I really appreciate that.
I echo your sentiment as the last film had the Strawhat crew, the supernova and their allies take on a former member of Roger's crew who still carries immense strength and power. In the manga/TV series Luffy has fought his toughest opponent yet who's had stamina for days and was only defeated through a team effort and Luffy experiencing another power up (one I was happy to see). Its about time that a One Piece film had a different type of antagonist that wasn't a case of "I'm incredibly strong and powerful, come at me".
Let's face it. Chances are the next OP film will have an antagonist that has links to one of the series' great pirates and will be mega strong in order to satisfy the shounen hordes once more. On this occasion I'm glad that film Red went down a different path (I'll make the arguement that the film's title should have been One Piece film: Uta though).