How about a "rain plasma rifle", a modification which produces a splash of burning plasma?
Since the original plasma mass gets divided, the resulting shots create only a very small AoD, but the group of shots covers a wide area virtually deadly trapping everyone inside.

I'd say operation should decrease CPU usage further. The thing is a leech.

Personally, I'd like it to be superior in damage to that of the Swarm launcher, thus making it a rewarding skill AV weapon. It's already CQC because of it's arc so there's no point in having such a weapon do so little. As the swarm advances through levels it receives +200 damage. With the plasma cannon the difference between STD and PRO is basically 200.

A lot of people are concerned that the plasma cannon, should it get buffed, will result in the old Swarm launcher. But in essence it couldn't be farther.
Old Swarm:

• Dumbfire + Lock On
• Up to 6 missiles each with its own splash
• long range
• too accurate

Basically people were sitting on mountain sides (sure I did it once too) and shooting missiles at people from longer range by basically lining up the square. The plasma cannon is so different. One shot, major Arc, one shot per clip. Buffing damage and fixing it will not put it near old swarms. The plasma cannon has splash and dumbfire therefore it can be used against infantry but it is far less efficient at so then people would give it.

The Plasma Cannon is one of the few weapons in the game that is exactly where it should be
It performs it's intended role perfectly and i dread further tweaks
atm you are putting your ass on the line to use it in exchange for the high dmg
It is not an AV weapon and to have more than a 1 shot reload system would be madness

We already have 2 very powerful AV weapons, swarms and force guns. Why not make the plasma launcher an anti-infantry weapon?

7m splash, 400 damage, no direct damage, 6 sec reload. Good for weakening clustered mercs, but not spam able like the mass driver.