Controversial for some, but I think the ACU gun upgrade isn't really worth it. Reason being is that it has a tendency to overkill in the sense that it fires on units that already been killed, wasting a shot that could've went to other units.
Example scenario with the gun upgrade:
10 Strikers each with 300 hit points.
Takes 3 shots ( Vanilla ACU gun doing 100 damage each)
With gun-upgrade, high potential for a wasted shot before re-targeting the next unit. Wasted shot damage is 100. Wasted shot is due to the following reasons: Range between ACU and target, Fire-rate and Projectile speed. These issues all add up to wasted shots.
with 10 Strikers x 100 damage wasted before re-targeting = 1000 missing damage.
You could've killed a extra 3 more strikers (Since strikers have 300 hp x 3 Striker units = 900 damage needed to kill 3 strikers) with that missing damage! Huge!
I propose the following:
Instead of a faster fire-rate. Make the gun-upgrade increase damage instead, while keeping the fire-rate the same as a Un-upgraded ACU. Matching the dps that would've been gained from a fire-rate increase. This would decrease overkill dramatically.
So for example: IF (I'm not sure) the fire-rate increase on the current gun upgrade increased dps to 300. 100 dmg-per-shot / .33 fire-rate = 303 dps.
THEN:
with my gun upgrade proposal the damage would be. 300 dmg-per-shot / 1 fire-rate = 300 dps.
So it would be the same dps that we have now, just put into damage instead of fire-rate. Thanks.