This right here is just my opinion. If you hate the buffs/nerfs, reply, and I'll take them into consideration.
The Buffs
Auto Tanks (Auto Gunner, Trapper, and Smasher)
This is a simple buff. The Auto Turret has a separate stat called "Turret Power". This Stat is separate, has every bullet stat as one, and is only upgrade when the auto gun shoots polygons and Tanks and "Gains EXP." For Auto Smasher, the bullets stats are not there, only on the Auto Turret's Stat.
Trappers
Trapper: Trap Speed buff (Goes for all of them)
Tri-Trapper: 30 seconds for trap life.
Gunner Trapper: Slightly increased reload for the front 2 barrels.
Smashers
Body Damage Resistance back
Landmine: Turns invisible faster
Gunner Branch
Gunner: 30% more reload
Auto Gunner: Already said.
Destroyer Branch
Annihilator: Increased Damage
Tri-Angle Branch
Booster: Higher base recoil
Overseer Branch
Manager: Slightly Higher Reload.
The Nerfs
Overseer Branch
Overeer: Drones spawn every 4 seconds. Delayed spawn time.
Overlord: Same as Overseer.
Destroyer Branch
Skimmer: Less recoil from missiles
Tri-angle branch
Fighter: Side guns don't propel the tank forward
=More are coming=