The plugin offers a large number of improvements over the basic embedding that Jetpack provides. For a start you have a lot more control over the output - Jetpack has limited options, whereas this provides all of the options available via the YouTube Player API.
These options are also set in an admin screen which means they become a default for every video you then embed. You can specify individual options on each embed, if you wish, to override any of these defaults.
You can set up multiple defaults and even create your own playlists via my plugin.
Converting over shouldn't be an issue, as my plugin provides compatibility so no changes are required (other than maybe switching on an option in my plugin's admin screen).