I was previously using Wordfence which was causing high IO and Memory usage during its periodic scans which seemed to hang part way through. I’ve no such issue with Shield plugin. I can’t comment on the spam filter as I’m using the alternative, but good that there is no conflicts between the plugins. I’ve been able to disable two other small security plugins since Shield plugin includes the functionality. I’m yet to explore all the Shield features and logging, but so far all good. Great plugin considering it’s free.