As of 10 June 2015, tank cannons and artillery cannons aren't very convincing of being all so very powerful and destructive. Their sounds are somewhat muffled and don't convince me I'm in a combat environment.
Also, the artillery seems to shrug off recoil like its so high and mighty. The artillery would look way more powerful if the anims were more violent, i.e making the barrel recoil at a faster speed and thus having that barrel affect the tank as a whole (pushing it back or bringing the front up or whatever).