I am not a techie. I count on plug ins to understand the things that are beyond my expertise. I like WordPress SEO because it is extremely complete, without being so complex that I am tearing my hair. I can use the suggestions there, or learn more if I want to. The Yoast reputation for good service can't be beat. And one of the first things I look at in a plug in is how frequently it is updated. Yoast seems to always be on top of every change in WP and the general web atmostphere.