We use PRTG as a monitoring tool, to observe consumption and latency of our configured links in our edge router, and also use it as internal monitoring and support in the development of graphs and reports.

Cant beat the pricing for what you get. It works as intended

The software is very easy to both setup and manage. You can start from a first time setup, and then scanning and importing your environment with default recommended sensors in under an hour, which would provide you with a very good starting point to begin further refinement. The product is very reliable, and can be setup in an active/passive high availability mode that is included with the base license. Once HA is in place application upgrades are a simple click and the application takes care of the fail-over/take-over process. The base product covers all of our monitoring needs. From network infrastructure (switches, firewalls, loadbalancers) server infrastructure, and external websites and services the out of the box product should cover the majority of environments. For more advanced needs scripting (Powershell, Batch) can be used to query and output information that can be ingested by PRTG for display. Remote probes can be used to gather monitoring information from systems and sites that are outside of your network and do not require typical persistent (VPN or other L2/L3 technologies) to monitor remote systems. Once the product is tuned to your environment knowing when a system or resource is about to have issue and receiving an alert that you can choose to take action on via an action (built into the product) or some human intervention will assist in making your IT group more proactive.