Fortigate firewalls are feature rich and unlike some of their competitor if you forget or decide not purchase maintenance they will still function albeit with reduced functionality as opposed to stopping, support sometimes could be improved for corporate customers, but all…

Most support some form of identity-based policies based on LDAP and/or AD and it won't be a simple straightforward decision, choosing the one that best fits what you're trying to achieve and your budget.  Look at things like cost (is it an add-on or comes as part of the base…

Depends on the firewall and its purpose, but a rule of thumb is to buy based on all UTM features turned on, e.g. protected Mb throughput.