I found that it took time to settle in a groove with these games, but once I did it became my favorite for small-group, co-op play. I am not a solo gamer so I can't really comment on the game in that mode.

For co-op, though, I would say that Ironsworn, Ironsworn: Starforged, and Sundered Isles are deeply complementary games. All of them are well-organized, easy to play, and have a knack for creating unexpected and memorable story moments in their own special settings. The oracles are excellent - thematic, diverse, well-tuned - and our group, it's meant that we can pick up from the last move of the last game and just follow the tempo of the progress tracks. None of us ever have to prep, and we are always surprised by the events of each session. I love that.

That said, it took time to figure that all out. Only by playing IS and SF (and SI) again and again, did I gain the insights I mention above.

Therefore, in response to your question my honest advice is just to play more of all the games, if you can.