Both products has their pro and cons. However in term of subscription and pricing for a small office, this offered better ROI as the office didn't want to spend too much and have something relative easy to manage.
I will recommend SonicWall depending of the size of the company and the knowledge of the personal is going to administer the firewall. I deploy those in small office settings where manageability was relative non existence.
Technical support is a little expensive but it works. Any technical problem or not, SonicWall support helps in solving the problems. The SLA is fast and the service is also cordial, functional, and straight to the point. Support is essential to keep the tool always up-to-date with lists of malware, URLs, attacks, and others.
Both products has their pro and cons. However in term of subscription and pricing for a small office, this offered better ROI as the office didn't want to spend too much and have something relative easy to manage.