I've tried this plugin starting over a year ago. I had some very significant problems with it throwing errors and not rewriting titles correctly per the settings I had specified in the plugin. I deactivated it and went on with life.
Fast forward over a year later, and now it's been renamed to include "WordPress" and the hype is even greater. I decided to take it for a spin again, hoping it had been improved. Big mistake. It actually deactivated the Google Analytics plugin (I know...hard to believe but true) and caused several other problems on the site.
My advice: stay away. Lots of the things that this plugin does is old news when it comes to SEO anyway. You could seriously cause more problems on your site than help if you don't know what you're doing.
Write good content that real people want to read, share, and save. Period. Leave the hype behind and enjoy life :)