The plasma cannon will soon become extremely powerfull in combination with Lai dai packed av grenades after the patch drops. A proto plasma cannon will deal 1502 damage and lai dai packed av grenades will do 1586HP damage each (3172,5 when both nades hit). So the light AV weapon will outperform assault forgeguns with a single hit but not on the DPS side. And the av grenades will pack a heafty punch too. Combine that with a cloaked scout and you will deal massive ammount of damage very quickly. And if you hit the weakspot with the plasma cannon the damage goes trough the roof.

In regards of how to use it then i would do this:
-sneak up and fire the plasma cannon in the tanks bum (bonus damage and shields getting stripped)
-stay close to the tank and throw your av grenades (no shields= more damage on armor which is +20%)

so without the weakspot hit a plasma cannon with proficency V will deal 1877,5HP without damage mods against shields. the av grenades are going to deal 1903 damage and when both hits that is going to be 3806. So the max damage without the weakspot would be 5683. That is quite alot of damage dealt very quickly. And to be honest im getting a bit jealous at the guys who specced into plasma cannons.

Your argument would be sound...
...if the PLC had twice the projectile speed that it does now (i.e. similar to a rocket/RPG launcher in any other game)

Considering that 80% of the tankers out there (aside from mlt vehicles) are armor based, the damage increase shouldn't really affect tanks as much besides maybe scaring them away easier (sadly)

What we all need to realize is that because blaster tanks will no longer be able to SNIPE across the map with their BLASTER (due to the dispersion increase), tankers will be flooding the forums complaining about AV (specifically the PLC and AV nade buff). Dispersion prevents blaster tanks from killing AV targets easily from medium-long ranges, which is proper balance.