Once again, a BIG step down from it's previous counterpart the Rocket Launcher. Firstly it's not as effective on the more powerful aliens. More importantly, you can't fire it on land! (though it can reaction fire due to a bug)
It is still the most powerful weapon you can get your hands on without researching better weapons, but land missions pop up often enough to cause problems.
see [Rocket_Launcher] for more tips.