I think that a problem with Babylon 5, but also with DS9, or also with any SFF set on an island, so include Lost or any fantasy island, is that being stuck on a space station or on an island, the stories and the visitors must come to you. With a ship-based story, you can go anywhere the writer's imagination will take you, but more crucially, you can visit a completely different place each episode.
You would expect that after so many different TV series set on a spaceship/starship/TARDIS, that people might be bored with that format now, but obviously not as they are still making them. So, I do think that the ship-based series must work better.