Just wanted to report my results after implementing Jim's changes: I tested a blog post with 7 in-post images, several background images in the design template and 1 CSS file. I ran it 10 times each before and after the change at [webpagetest.org...] set to "First View Only" (to eliminate caching effects). Average results:
- Time to first byte received: 0.870s
- Time to start rendering: 1.815s
- Total load time: 3.145s
- Time to first byte received: 0.718s = -17.5%
- Time to start rendering: 1.547s = -14.8%
- Total load time: 2.908s = -7.5%
Quite impressive! Thanks a lot!