Experimental: translate3d() for block / world pulse effect, attempt at GPU compositing / reducing paints. Step-based keyframe animations for pulse effect, as well. Seems to perform worse, presumably due to doubled number of DOM elements (~1100) and thus expensive "recalculate style" work. Related screenshot: http://flic.kr/p/eHbgpf
Chrome-specific GPU compositing tweaks (DevTools optimizations) using transform: translate3d() vs. .style.left/top. visibility: hidden/visible instead of display: none/block for all, and no more removeChild() / appendChild() (likely expensive / layout thrashing) for all. Experimental translate3d() for world pulse effect, as well (performs terribly on dev machine.)