This plugin is great! One note on the installation instructions - the step about enabling auto embed isn't in WordPress 3.6.x -- you don't have to do it.
Also, don't put the actual iframe code in your post. Do what the installation instructions say in point 4 - WP automatically turns links into embedded videos.
*Also, to avoid videos from "filling" the page while they are pulled from the respective provider, just add a CSS class to the container using "overflow:hidden" along with max-width and height parameters.
Thanks for the plugin!