Gladio's DLC's set up is a bit boring and dissapointing tbh. They said that it's going to reflect on his character, his family and Cor, so hopefully it'll become more personal rather than "I gotta get stronger" (which, admittedly, really fits his character).
Maybe it's me projecting my own assumptions of what Prompto and Ignis' DLCs are going to be like, though. Although I remember Tabata saying that Gladio's adventure was going to focus on action, while Prompto's would do such thing in regards to character development. Ignis' was about strategy I think, whatever that might end up meaning.
The combat system doesn't look too amazing, but I can't properly judge until I play it (which I don't think I will. Not soon enough, anyways. If it's a good piece of content, I might think about it, though).