Appmon or the "new one"? Appmon was..a cluster fuck in the latest years for me.
Was really happy to leave it. But a few years later we tested the new Dynatrace and that shit is really shiny. Sadly, cost is expensive unless you are working in enterprice level, so cost is not an issue. But with the massive fuck up of newrelic/DD/Splunk with their skyrocket licenses.. is the cheaper option.