I would imagine that depends on your setup. We do monitor servers in both at this time.
We have been using Azure and AWS mostly as DEV environments to explore use as production. But that said, the IP Subnets are directly accessible from our management networks here. There are routes to that environment and enough bandwidth to manage them in NPM.
Early on we explored the Cloud integration in SolarWinds, but at that time, the vendors wanted to charge extra for the API's CPU cycles and the bean counters nixed that. We have not gone back to exploring that option.
