We heavily utilize this plugins with 4 separate models created in our master for different AMIs for different type of build project.
While the scale capability is great, we do encounter high frequency of out-of-sync slave. This means that we have Jenkins slave being marked offline, but the actual EC2 instance are still in "running" state instead of "stopped" state.
Not sure if it is something to do with AWS side unable to stop instance, but at least the Jenkins.log does not indicate that is the scenario.
Given the high volume and high frequency of this situation, we are actually bleeding money without added build capacity for those out-of-sync slave.