Factor 4 improvement of the First Meaningful Paint according to PageSpeed Insights.
On mobile device with slow 3G connection, visiting from Dulles (United States), difference in First Meaningful Paint is 7.9 seconds (3.0 in optimal situation versus 10.9 seconds in previous situation).
Obviously, as a visitor you also want to be able to start reading as soon as possible. Because I also optimized loading of the fonts, the difference is (once again) 3.0 seconds versus 12.2 seconds (a difference of 9.2 seconds).
On desktop, average 3G from Amsterdam this same comparison resulted in 6.0 versus 1.5 seconds.