JBsourcery has always been one of the most customizable roms for the Galaxy Nexus. This Rom is based on 4.2.2 AOSP. The Sourcery team has always implemented their own theme engine that is updated frequently with new themes that match the concept of the Rom itself. JBSourcery is introducing lots of new features in their latest version 5.2. They have totally redone the NavBar, NavRing and Toggles. Some other new features include New Kernel-Faster, an updated sourcery dashclock, updated sourcery tools (faster and uses less data), New theming in tools for contacts, blacklist inphone app, ability to dismiss calls, magicclock redone, Pie Controls, and much more.
This Rom looks to be even more customizable than ever. With the addition of speed tweaks and other performance enhancements you can't go wrong.