The Power of Crosswalk
The immediate benefit of bundling an application with the Crosswalk webview is that everywhere your application runs, it uses the same, Chromium-based runtime. This reduces or eliminates many of the headaches encountered with older webviews. (The web app run below uses Web Components and WebGL.)
WebCL: Accelerated Graphics
Building your web app with Crosswalk enables you to take advantage of new web app features and libraries. One example is WebCL which enables web apps to leverage the GPU to accelerate graphics processing. (The video below is a screen capture of an arm-based Nexus 7.)
SIMD: Parallel Execution
The "Flocking Birds" web app to the right continually calculates the position and velocity of each bird. It tries to add as many birds as it can while maintaining ~30FPS.
About 17 birds can be generated without SIMD and about 32 birds with SIMD enabled.
(The video is a screen capture of an x86-based ZenPhone5.)