Smoothwall SWG is very suitable in companies where there is a lot of staff and power to distribute the bandwidth by areas and give priority to the staff that requires better service. It's also well suited for business that require protection of their data and services as it is constantly monitoring the network and does not let them enter dangerous sites.
If you already have Webroot AV, it makes sense to continue with the same vendor. It's pretty cheap compared to some solutions, so it might be the case that it's this or nothing, in which case this is a no brainer. If you are an MSP, this is an easy product to sell, and requires very little maintenance. you do need to monitor it but it runs itself most of the time. If you are a customer with >50 users, you should really be looking for a product that is a bit higher up the food chain
Real-time IP filtering is very favorable. That helps limit and restrict prohibited content.
Elaboration of personalized reports of the activities or pages that users visit to make new blocking rules to the pages most visited by users that may damage the functioning of the servers.
Enforcing organisational policies regarding internet usage, such as blocking access to certain types of websites (e.g., gambling, social networking, etc.)
Smoothwall SWG has many tools similar to pfSense but in my opinion I like the graphical environment of smoothwall swg more. It is more didactic and simple to use for new users. Also pfSense lacks the tools for monitoring in real time and the elaboration of reports that helps to perform statistics on sites visited.
This software helps a lot and is very economical, since it is free and it can be installed in equipment with low performance. That is of importance to companies with little budget or who are just starting out in the market.