The thing that I mostly ended up butting up against was reloading. Although the guns "recharge" rather than swap magazines, there is no time bonus for recharging one shot over an empty battery.
So it always makes sense to fire all shots in all guns unless you have a significant break.
That's fine, but then also if you change weapons mid reload you get no credit for having completed 99.9% of a reload. You have an empty gun.
The cherry on top is then the MMB to activate your AOE makes it very easy to accidentally switch weapons.
Many times I would be weaving around waiting for a reload to finish, press my MMB to activate a life saving AOE, accidentally switch guns to another empty one, and be back to waiting for a reload.
I know the solution is git gud or remap MMB, but I felt like I spent an awful lot of time reloading guns.