It depends how many pages each of your visitors sees.
This drastically improves the performance of the first page of a users session. It gets it down from 800ms to 400ms because there isn't any waiting around for additional resources.
On the other hand, when everything is inline, all the resources have to be served on every page view. If you have large JS, CSS, and images; you don't want to have to keep resending as the visitor views more pages. In that case it is a good idea to make the first page load slightly slower in exchange for faster subsequent page load times.