Biggest difference is being able to execute INSTCMD commands, at least that was the main reason why I developed my own tool. Another less important differences are: older ARM support and since it’s written in Rust, it’s much more efficient in terms of resource usage. TBH, being that efficient only makes sense for very low-power devices.
Besides that, I don’t think you can go wrong with either project.
I personally use Traggo, but TimeTagger is also a great option: https://timetagger.app/articles/selfhost/
I’m currently using InfluxDB + Telegraf + Grafana combination to monitor Linux systems and k3s pods. It’s basically same as Prometheus, but InfluxDB uses push model, which makes it easier to develop tools for collecting custom time series data.
For alerts and dashboards, I think Grafana is the simplest and most hassle free solution available at the moment.