Fawkes is stupidly overpowered, yes, but the thing is, when I got him the first, there was nothing left but a bunch of supermutants I could two shot with ol' painless so it didn't matter much. And the second time he joined, 95% of the fightining was done by the giant robot. Even I had trouble finding things to actually kill with LP around, and I can stop time. Not much use to be superpowerful when there is nothing left to kill.
Big guns are useful for 1 reason alone. The flamer. If you take that and the pyromaniac perk, it becomes a roomcleaner. And really, pyro is a very nice perk. 50% extra damage is never something to sneer at, and it covers at least 3 different weapon type - melee, heavy, and energy (the special alien blaster).
Plus, splash damage doesn't tend to disrupt sneak like direct does, so you can be a rocket ninja. Yehaw.
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