Hey there, @MeepsterNotchy!
I'd definitely second @drtweak's opinion about the utilities being equally good. Moreover, using a third-party tool together with your HDD's brand-specific diagnostic utility is definitely a good way to benchmark the health and SMART stats of that particular drive. Using the HDD's brand-specific tool is recommended because the SMART health/failure criteria may vary from one HDD manufacturer to another. The most important thing is that a healthy drive should pass all the diagnostic tests from the manufacturer's tool.
Either way, these monitoring/diagnostic utilities definitely won't save you from data loss if you don't do regular backups to multiple locations (on-site as well as off-site). If any of the...