I really liked the changes made from DoW to this.
First off: Having to choose an avenue of fire for your machine gun teams is awesome. (Instead of simply putting them somewhere and having them shoot anywhere, you have to set their fire line, so they can cover a specific street and stuff.)
Second: TANKS HAVE POSITIONAL ARMOR! Hitting a King Tiger in the front does nothing. Hitting them in the back though, blows them up. You have to manuever your tanks behind the enemy. This and the avenue of fire add real strategy to the RTS genre.
Third: You must have a line of supply to each resource zone. I really like this. You end up with real battle lines, instead of random crap.