Originally Posted by Kuhns787
What is going to be so good about jb?
Project butter - OS enhancements such as buffer tweaks, increased frame rates, a system which keeps rendering and touch input events in sync better, and touch prediction come together to make everything run just a little bit better.
Other features receiving addition/enhancements are notifications, offline speech to txt, notifications, google now, and voice search:
Google Voice Search vs. Siri (Android 4.1 Jelly Bean) - YouTube