I havent played this game in months, but i wonder if the canister was made better for the vanguard and harasser and if it is viable on either vehicle. I remember in the days of yore it was pretty bad but I will still maintain my hope in the lovely canister.
They were buffed one day, they are probably IMO the best Empire Specific AI for MBTs and Harassers, but you've got better options, like Halberd or Enforcer, which can snipe infantry and deal good amounts of damage to other vehicles.
They had their magazine size buffed to 8 (originally 5), total round capacity changed from 100 to 160, pellet count increased from 8 to 12, Velocity increased from 225 to 400 and projectile gravity is increased from 1 to 7.5. Those were the big ones. Overall, you get OHKs about 20m and it melts Flashes and Harassers, but you can't deal with heavy armor like Sunderers/MBTs/Lightnings. It's still situational, but much better than before, and if I remember correctly the buffs took place at PU 02.