The Meteor Mobile Missile Launcher (often abbreviated as MML) is a UEF indirect-fire missile unit. The Meteor fires a large group of medium sized rockets, that can easily overwhelm tactical missile defenses. However, its missiles don't hone on targets, and small and agile units can easily avoid them. Nonetheless, it is good against structures and large, slow units, like experimentals.
When assaulting a well fortified base, consider using both Meteors and Demolishers. Use the Meteors to pick off base defenses and high damage units, as well as knocking shields offline, and then use the Demolishers to bring the pain. While the Demolisher's area effect damage is superior for hitting tightly packed bases, it is a weak unit, and does not have nearly the range of the Meteor, so they work best in tandem.
Meteors, Demolishers, and any long range unit in general are typically weak and will always require an escort. For the UEF, Rock Head Tanks do very well at this.
Mobile Missile Launcher (MML) can easily deplete shields. Use them to break shields fast and easily. Be sure to protect your mmls, because your opponent will respond by attacking your mmls. Tanks and others can do this job. Then, when the shield is out, send in your attack force and destroy him.