Users express a high level of satisfaction with WP Security Ninja, praising its user-friendly interface, effectiveness, and comprehensive security features. They find it particularly helpful for simplifying the process of securing WordPress sites, offering extensive security tests, malware scanning, and a configurable firewall. The premium version is highlighted as worth its cost, providing additional useful features and excellent customer support. However, some drawbacks include the persistent notification for data usage consent from freemius.com, which users find annoying. Additionally, some users experienced issues that were not easily resolved and mentioned that certain features only accessible through the paid version. Despite these, the overall consensus is highly positive, deeming the plugin a valuable, efficient tool for website security.