Which version do you prefer?
In recent gameplay we get a good look on how the pulse grenade works. Instead of the giant kill ball like orb that explode, drains then implode. It now explode leaving micro mini orbs behind, each mini orb explode dealing damage apon contact. A well place grenade will kill without needing to finish off the enemy unlike halo 4 version which requires shots before or after damaging an opponent with the grenade. I can't remember exactly but I believe it did bounce like a frag so the benefits the halo 4 version had of instant explosion is no more.