Outdoor base turrets have changed as well. No longer are you stuck with the standard turret that was put in place by the mapmaker. This time, you can get some barrel packs and upgrade the turrets as you like. You can turn original outdoor turrets into anti aircraft guns, flux cannons, mortar launchers and guided missiles. Plenty of fun toys to keep you busy for a long time.
Vehicles play more of an important role due to map size.
Some maps are so big that unless you use vehicles your heavies will still be making the trek long into the game. You have the Wildcat, which is a quick cycle for you to get where you want to go to fast. The Beowulf is a two-member tank where one is the driver and the other is the gunner using either of the built in chain gun or mortars. Jericho is basically a huge lumbering forward base and when deployed has a built in inventory station, missile turret and sensor jammer. Don't take this bad boy near water as it will explode on contact.