Have been trying to figure out what anti-virus or security suite is good for Symbian smart phones. Finally, I came to the conclusion, that Kaspersky mobile security for Symbian is the best. Not only on count of features, but also on count of usability and footprint.
Compared the others I tried out, it had a much less clunkier interface, good detection features and firewall capabilities. The others were simply too cumbersome to use and also to maintain. Cost was economical too.