Remix OS is the rom for those looking to increase productivity on their Nexus tablet. This OS is designed by ex-Googler's and is meant to give you a full desktop PC experience with all the multitasking abilities on your tablet. The latest version of this rom is based on Android 5.0.2. The rom features multitasking multi-windows, physical keyboard optimizations, keyboard shortcuts, and more. The advantage here is that you have your desktop experience, but you don't have to lug around a big laptop and you still have your app ecosystem, touch screen optimizations, and resource efficient operations. You will need to be rooted with custom recovery installed to flash this rom. Head to the link below to grab this rom.
via XDA