Well, this plugin removes all the extra css and js that is required to load the FB Like Box, and then caches that so it's super fast. Removing the *like* feature was a consequence of this.
So many people are requesting this feature, I think I have to include it in the next update. I'll see what I can do.
To answer your question, yes - using this in tandem with the FB Like Box should speed up the site since it doesn't need to load the user images, but not by much since you still loads in the JS files.