I was really shocked to see that heavy machine guns could move and fire as freely as infantry ! They can even attack in close assault, giving their bonus to the resolution... My imagination is large, but not enough to see how you can run, fire and CC with a 140 lbs beast !!! Modern assault rifles would not make a better job... Moreover, many MGs in strongpoints were fixed, unable to move in the scale of an assault.
To sum up, a great point of disappointment for me, that makes infantry assaults something nonsense, when you see MGs running and firing everywhere, in attack and in defense ( hit and run tactics : pinning fire... run to the next trench hex... pinning fire... etc... )