It is fairly easy to setup and use. I like the way you can have varying policies based on users and IP address ranges. Preset categories cover many websites, and can be useful if you are setting policies based on security only, or if you need to really lock systems down.
Room for Improvement:
AD authentication is buggy and not very effective. Sometimes the policies are applied immediately, sometimes after 5 minutes. The only sure way to filter is to set static IPs, which is not effective network management. Many websites are not filtered. Many categories don't include commonly used sites. Malware can slip through easily.
For the functionality, the price is fair. Easy to manage and simple to deploy if you are using basic features. Tech support is not very helpful. I have suggested numerous changes that could be made, but nobody responded.