Which SEO content analysis plugins are you using? I am not referring to SEO enabling pliugins like All-In-One-SEO-Pack or Yoast's WordPress-SEO. I am looking for opinions about some of the plugins that actually review and rate the quality of the post content, such as ClickBump SEO!, Easy WP SEO, WP SEO Beast and others.

These are typically paid plugins, so I don't want to invest in any garbage for a test.

All of the reviews that I find appear to be written by either the plugin authors or affiliates, so I don't trust them. I am looking for some real opinions about whether or not any of these plugins actually do something worthwhile.