Brace yourself, NW 0.15 is coming

Still in pre alpha version, I really hope to see moar performance improvements

You can get it from the NW repositary.

An easier way to test ahead would be to install Chrome Canary and try previewing your game in that. It uses the same browser engine, auto-updates daily and you could set it as your "custom" preview browser. Note it breaks from time to time though since it doesn't get as much testing - the dev and beta channels are a little further behind but better tested.

While this is (certainly) true for the basic performance etc. I often found that NW.js exhibits problems that chrome doesn't. Jank were none was present in the same chrome version, the whole business with the dead processes and inability to quit, the fullscreen issues, to name a few.

So whenever they have something new I grab it as soon as I can

I hope they improve NW CPU and memory usage further.