this article left out the importance of IO. from our past experiences w/ several projects, implmenting SSD/SAS were the single biggest improvement in performance (as you can notice right away visually), all the other optimizations (minify/yslow/etc...) were just very subtle improvements. CDN is very good at relieving load off your server and comes in pretty important at times of HN/Digg/Slashdot effect. been toying around with cloudflare lately and I think it's a good replacement for your DNS hosting. it gives you CDN out of the box just by pointing your DNS at them.
