Re: 100 gr broadheads vs. 125?
If the factory arrows have aluminum inserts up front, I suspect you will get better flight and accuracy by using 125 grain heads. It improves the FOC balance which is important with crossbows. If your arrows have brass inserts up front, the 100 grain heads should be ideal.
You will lose a little speed with the extra 25 grains but your kinetic energy will bump up a bit.
I support all hunters, regardless of weapon or technique!