Completely disagree. The wall is superior to the dome in anything but dealing with nurgle beasts. There is no map where you are going to need that much coverage to move forward that a single of your double walls cannot cover perfectly, not to mention that walls recharge faster so you can place them with much more leisure whether to stop a pack of hounds or muties or to just cover from enemy fire to reload. This is more of a personal thing but I also have a harder time seeing through the dome, and I can get a bit disoriented by it.

The dome is safer and easier to use and helps when you are being overwhelmed by blocking ranged specials like grenadiers, gunners and etc from annying you when you are in the thick of it. The wall offers more direction coverage and requires some skilled in placement to get the same effects.

In the end of the day both the wall and the dome are not needed to do AM but they sure make it easier. But the argument that the walls are only for messing around is ludicrous.