Which Alerting mechanism to use for Loki and Mimir?

Hello Community.

We have a new self hosted installation of Grafana with Loki and Mimir. Which is the recommended alerting mechanism to manage alerting rules? There is alertmanager inside Loki and Mimir, which could be managed trough Grafana. And there is the new Grafana managed Alerting. Any downside of using this? Is newer = better? I plan to stick on Grafana and Mimir, so Prometheus compatibility is not a concern. Maybe we switch to Grafana Cloud in a few years.