The mid rock was changed a bit to allow mid to be challenged from red cave.

Sentinel beam was moved to be on top of each base platform for better base defense against vehicles.

Carbine replaced the Classic BR by the mid dam support.

The Spartan Laser and Grenade Launcher locations were swapped - In doing this, it was a difficult decision since the Splaser was always in mid on this map since Halo 3. However, no more can you just grab mid to remove enemy vehicles and steamroll. This switch was to provide balance and promote better map flow with less map control from mid. I understand this may be undesirable by some who enjoy mid map control, but overall it helps balance the map locations and CTF/Assault gametypes by allowing the ground vehicles to survive better.