Geth pulse rifles are comparable to a standard stock assault rifle, but finely balanced with low-recoil and incredibly high accuracy. The pulse rifle fires a rapid stream of light-weight slugs which are wrapped in a phasic envelope to increase their damage.
Damage is the Pulse Rifle's crippling shortcoming, inflicting far less damage than any other Assault Rifle. The damage is so low, the only weapon with a lower damage per shot is the Geth Plasma SMG. This effectively means whereas some rifles would kill in about 3-5 shots, the Pulse Rifle would require 10-15 rounds - a margin that will likely be further widened against armored targets. To mitigate this problem, apply appropriate mods, use appropriate powers and aim consistently for enemy heads. This is especially useful as the Pulse Rifle has a damage multiplier of 3 for headshots, compared to 2.5 for most other weapons.
The weapon's slow reload time is another significant factor, rivaling the Revenant. However, it can be "reload cancelled"; sprint or perform a dodge maneuver or stand perfectly still momentarily while pressing the action button when the steam blows off. Run practice drills in the Spectre office's shooting range to time it right.
The Magazine Upgrade would really benefit this rifle, giving 180 rounds per clip at Level 5, giving it the highest clip capacity of any weapon in the game along with the N7 Typhoon and the Geth Plasma SMG (180 rounds maximum with the Assault Rifle and SMG Magazine Upgrades both at Level 5).
The Piercing Mod is questionable at best as its already low damage will be decreased to insignificance whenever piercing cover, the damage is even less than the Geth Plasma SMG.
The Scope is not necessary because it's already pin-point accurate. The Stability Dampener, though is minimally effective for the same reason, makes the very little recoil even less noticeable.
Using the Geth Pulse Rifle with a character that can increase its fire rate, such the Turian Soldier with Marksman and the N7 Destroyer with Devastator Mode, can increase the weapon's effectiveness.