The most valuable features would be content caching and content compression. It also has an inbuilt firewall. I doubt whether any other ADC supports this firewall feature. It also has a web application firewall feature.

The most valuable feature is its simplicity.

The interface is user-friendly.

The most valuable feature is the SSL offloading capacity.

It is easy to manage and easy to configure.

I like all the products in the Fortinet family, they are simple to use and you can integrate a virtual server in a couple of minutes. If you have the topology, if you have the network, you can make a virtual server batch in a couple of minutes. It uses the same FortiOS regardless of the product. 

My experience with Fortinet has been very positive. It provides a great layer when it comes to SD-WAN and other security capabilities. It offers many models for a host of environments. 

I like the solution's load balance with DNS intelligence.