Disregard anything you hear about the AI being dumb.
They react differently to any disturbances in their patrol, if they hear the smallest thing they'll peak or pull their bodies around corners to see what's going on. In combat they WILL engage and will try to get shotgunners to flank you. In the later parts of the game
[spoiler]on top of the above, ordinary grunts have augmentations (such as cloak) when you engage them in combat. Total ballwrecker.[/spoiler]
There's not been any real issues, they've locked me down whenever I've been on alert.