1. They Own most of the territory throughout the wasteland which helps with exploring
2. Most Rare weapons are on that side of the map in their territory
3. u will get the lucky shades and the rare machete
4. The legion is much stronger than the NCR I once saw 1 legion centurion take out 4 rangers 2 of them in the black armor
5. these benifets rack up to good battle skills since u kill more with the Legion than the NCR
Hope This Helps from youre friend MrRager