Ion Plant is cheaper than any other power plant in game, it is built much faster (those stats are still subject to change, so I won't write them in numbers). It gives SW general opportunity for rush, expand faster and take more control of the map. But, in order to balance it, you cannot upgrade System defense on it anymore, because player would attack with these structures. Also, it brings less power to you. So, you will need to make very large number of them to support your base. It has less health, and when destroyed, causes a small EMP explosion, shutting down all nearby tanks and structures for a few seconds. You cannot purchase more energy production on it like you could on other USA power plants. It has a nice rotating animation and awesome lighting effect.