As everybody else have said. This add-on does what it says. I've seen my members amazed and felt happy by how things that can be embedded are by default embedded on their posts. Be it a pastebin snippet, a tweet on Twitter, or even a poll widget. Support from the author is also great. You can expect quick bug fix and continuous update. Totally recommended to install if you think that it's too much of a hassle to manually add more media sites to your XenForo installation.
Can you describe to me how you find the default YouTube BBCode better than the one in the pack? That would help me figure out whether and how I should change it, thanks!