According to the release notes, Aliens: Colonial Marines Overhaul version 5 visually improves all levels. Moreover, this new version of the mod adds permanent decals, and improves Pixel Shader for better graphics.
Naturally, this mod also improves the AI. The team has reworked AI Targeting mechanics to improve xeno and human combat, and slightly improved the Human combat AI. In addition, it brought significant improvements to Xeno dodging and jumping.