I've selected the Flash grenade as my LA grenade. Main issue with it is you cannot tell if or how effective it has been. It would be cool if when you flash a target their stance changes to reflect their state. On a troop they should put their free hand to their eyes to indicate that they are blind. If they have been fully 'whited' then their hand should be up to their eyes. If they have been partially blinded then their hand should be up but not covering their face. A Max is a bit more tricky, I thought that the charge animation would work as they cover their faces with their arm already. However, the Max can shoot with both arms and they can still shoot whilst flashed so - how about they put their heads down and shake them to show their disorientation. A hit marker would also be useful.
