I’ve just completed the same mod you did. The sound quality is, as expected, not great, but it is a lot louder! I think this will work for watching movies. It was a struggle to hear quieter dialogue on the stock speakers.
This has got me thinking, though. This speaker seems like it might fit under the overhang I’m already taking advantage of for my wifi antenna mod. I could work a grille into it and maybe get even better results, with less space taken up internally.
I’ll post a new thread if/when I get around to trying that idea.