I have deployed FortiGate with multiple organizations such as universities, government institutions, healthcare, and ISP providers. I have worked with FortiGate models 30-500 series and I have deployed the 3200D model for one of the broadband service providers located in India, Namely Sikka Broadband.
I have installed the FortiGate 500 and 400D to replace a Sophos firewall in a main corporate office. This implementation provided improved network performance.
This solution made it easier to connect all of the branches together via an IPsec VPN and remote users with SSL VPN.
The most valuable feature is the VDOM, which allows the customer to have multiple firewalls in a single campus.
Using the FortiGate security solution provides comprehensive visibility and advanced layer 7 security, including threat protection, intrusion prevention, web filtering, and application control. They face a major complexity hurdle managing these point products with no integration and lack of visibility.
Thie solution provides a high-performance inspection of clear-text and encrypted traffic.
The FortiOS Operating system is robust, and the WAN load-balancing very much transparent.
Improvement is needed in the Web Filter quotas to restrict users with allocated quotas.
It would be an improvement to add a feature for active users to change/reset their own passwords.
Fortinet renewal prices for all models are too high, so they should offer discounts for customers on renewal.
I have been using this solution for almost seven years.