I think this probably comes down to a need for improved AI on co op. I think if we had "smarter" bots to play against then you'd see an increase in difficulty. We don't have that yet, so as GSG_9_LIGHTNING said try custom servers, you'll have a far more rewarding co op experience there.
@pacalis I have no idea as to the reason for the bot AI's lack of consistency. I'm not sure if it's intentional, or if it's a by-product of their coding, or something else. As a player of video games I know that I don't like the current AI and the way they behave. I want to feel challenged during a Co op game (increasing the bot's accuracy just doesn't cut it for me I'm afraid).
As for speed running - ruins the game for me
Glass should be penetrable with one shot - definately.
The truck needs an ammo limit, or at least 100 rnd boxes that need changing. I think i'd prefer an overall ammo limit. I've heard arguments against that for PvP matches, but in co-op there is no reason to have an unlimited supply of ammo
I'm going to wade in here a little. I have to agree that the bot AI is underwhelming, and inconsistent. I play a lot of co-op matches with my friend, and the bots are 'dumb' for the most part and sniper elites for the other parts.
I've lost count of the times where the bots have seen one of my character's pixels and shot at it form the other side of the map and through trees (slight exaggeration) , I've been tracked through a wall (i'm convinced of that) and 180'd headshot.
But, I've also witnessed lines of bots running through molotovs and incendiary grenades to get to a location/target. I've seen bots miss from point blank range, completely ignore players, stare at walls while gunfire is raining down around them run in single file only to get mowed down.
There is no consistency in which the bots play, they either top elite snipers with god vision or Simple Jack's more stupid brother.
I want the bots to take effective cover, i want them to suppress me, i want them to flank. I'd even be happy for them to learn my play style and counter it. This is supposed to be a hardcore tactical shooter, it isn't supposed to be easy and right now people are doing speed runs through co op matches.
Having played commander for both sides i feel that the Insurgent's chemical mortars could be a little more deadly.
The chemical cloud itself should cause more damage.
It spread out a bit further when it settles on the ground.
Most importantly fall to the ground even if the targeted area is too high. Gravity affects us all.