I’m done with my copy of Even Faster Web Sites.
It’s definitely a book worth reading if you’re well into web performance optimization and want to step even further when all simpler optimizations don’t bring any more improvements.
Flushing early and CSS selector performance are important too, Steve was talking about it at Web 2.0 @ SF – CSS is a bit beyond my comprehension unfortunately, but flush is easy to comprehend for those who made at lease a single IO app, especially networked.
One thing among tools – in my opinion, WebPageTest.org was given less credit then it deserves – it’s connection view (next to the waterfall) and content breakdown chart as well as empty/primed dual run definitely bring it high in the “packet sniffer” section and not only “analytic tools” section. And I agree with Steve that it’s availability through the web give it a huge value in the eyes of developers and business decision makers. It’s very possible though that that section of the book was done when most of these features were added.