I can't add much to what has bee said already. I don't think you will see much differnce either way. I have also found that in order to make the bow more quiet it takes at least 50 grns of arrow wieght, and 75 is more like it. To effect penetration to any real degree you need to add at least 100 grns to the arrow. I have shot both wieght heads with great results. I would give it a try, if your accuracy improves go for it. If it gets worse go back to the 100 grn heads.

TAKE YOUR KIDS HUNTING AND YOU WON'T BE HUNTING FOR YOUR KIDS