I'm really perplexed by one of the central complaints in this slide deck. JS load time is just not a serious problem in my experience. The use of CDN's and the browser cache has made loading scripts almost irrelevant in terms of page performance. Its a problem for first time visitors who have a cold cache. And then it amounts to adding an additional 1-2 seconds of load time once and only once on their first visit. I really don't get bent out of shape by that. I'd be worried if that 1-2 second overhead was incurred with every single page load with every single user. that's just now what happens though.