It usually takes a bit to get into the writing flow, but once you get the grip it’s a great tool to improve your entire writing process.
There is a complimentary On/Off button in the TinyMce Tool Bar, for fast toggling of the plugin in specific situations.
Note- The plugin has a Settings Menu, named AutoComplete under the Settings Tab, which can be used to customize it behaviour. These settings are saved locally to each machine (browser, actually).