SCRIPT SRC via HeadJS
ms
Press CTRL+SHIFT+R or CTRL+F5 to reload with an empty cache = first impression.
View source to see how scripts are provided.
Time is calculated when window.onload fires.
Try with different browsers. The time difference varies a lot.
head.js() calls are always separate from the page rendering. Does not matter whether you load on HEAD or on bottom. You can also load programmatically on demand.