I’d say it has its ups and downs.
One upside is that the court does not have to delve into the question of truth as a part of legal proceedings.
It’s also worth noting that “true defamation” is only legal when you can prove it’s true. So it’s not really a freedom to speak truth, just a freedom to speak what is provably true.
I think the main problem with the Swedish law is that it places too little emphasis on the intent behind the “true definition”. For example I think it’s wrong to “defame” someone in order to gain control over a company, in some cases even if the statements are true. But I think it’s a very different thing to indite someone for telling their life story in a book, because a central part of their life is that they were the victim of a crime (see e.g. the chancellor of justice’s prosecution of Cissi Wallin for her autobiography).