Deciding what to choose with Conny

Hi everyone, a friend of mine, who is not in the group, is facing a decision regarding a rent reduction through Conny. Since I’m not sure what advice to give her, I thought I’d get some insights from this group.

She lives in a two-room apartment managed by a large property management company that has been horrible from day one, she is been living there for a year. Many things were broken, and they took forever to fix them, which caused her to pay more electricity and be without heating for some winter months. She joined a Mietverein, which helped her with the issues, and later also signed up with Conny to see if her rent could be reduced, as it’s a bit expensive.

The Hausverwaltung has now offered her a 200€ rent reduction, which would bring the rent into a reasonable amount for the prices nowadays. However, Conny is advising her to take the case to court, as they believe she is entitled to a reduction of almost 600€, which seems like a lot—it would make the rent very cheap, like the ones from old contracts.

Conny claims that such cases usually take around a year or less and that they win 90% of the time. If they lose, she wouldn’t have to pay anything, but the property management would withdraw their initial offer. This makes the decision quite difficult. She’s not planning to live there forever, but probably for at least the next five years.

What do you think she should do? Thanks!