Which is better for an atrial flutter: cardioversion or ablation?

Define better please: What does better mean? Initial atrial flutter ablation success rates run around 80-85%. This for the typical flutter variety. A form of atrial flutter called atypical atrial flutter has a much lower success rate. But ablation is invasive, meaning there is inherent risk such as perforation of the heart, pericardial effusion, need for permanent pacemaker implantation, etc. Such risks are very rare

Atrial flutter: ablation since it cures most of atrial flutter, cardioversion is only temporary measure to stop it.