It's clutch with the ammo regen, but I wouldn't say it's the best. It's good for those scenarios when you need to snipe and can't go pick up ammo. Gjallerhorn seems to be the most universal, especially for boss fights, but it seems like almost every exotic has its own uniqueness to them. Making certain exotics better for certain situations. Like icebreaker is great for oracles on Templar and bridge cheese on CE. Suros and red death are great for Crota cp. P&T is awesome if there is arc burn on nf or weekly. When the ir yut is singing, nothing else does more damage then 3 dragons breath shells right to her gut. Is IB the best? No I don't think so, but imo it is the most handy. I mean there are some scenarios where it be a little harder or you would need a lot of green ammo synth.