So far I've just gotten to the very start of disc two, and I've yet to switch from the Evangelizer and Negotiator, though I'm prepping some upgrade designs because as nice as they are I'm going to need more firepower at some point. A Diffractor Torus for certain. And I'm hoping I can kill the final boss with the Contact Beam this time--I played Dead Space 1 and 2 back to back before starting Dead Space 3, and managed to finish off both the Hive Mind and Nicole using the Contact Beam.