Halo CE: it not only took shields down quickly, it slowed down the enemy, and it took down guys without shields in a good rate
Halo 2: it was about the same... I have not played it in a while
Halo 3: it took to long to kill the people that had their shields down...
ODST: same as 3
Reach: it takes longer to kill some one without their shields...
Why can't all plasma rifles be like the CE one?