Well, Turret gun fire should overheat. In Halo 3, it was an instant kill weapon. You could fire it forever. In Halo Reach it was better because then they would have to stop fireing.
The Health Bar was awsome. I could actually see how close I am to dieing instead of guessing in Halo 3.
I choose small maps with power weapons. God help us if someone gets a shotgun.