In general it is a fantastic idea, although it might be even more or just normal fantastic depending on your build. Weighting will be better than flares on any hit where you were not already dealing rank 9 damage. If you are a more methodical/defensive build that uses 1615 and feint before each swing, I would be less likely to pay the price for the weighting. In those instances a flare can be as good or better and they are free. If you are any sort of build that swings sooner or against more defensive foes (especially using zealot), the weighting is about the best weapon addition you could get (except splitter).
Sweet is the sound of the pouring rain,
And the stream that falls from the hill to plain.
Better than rain or rippling brook,
Is a mug of beer inside this Took.
