I actually started with 125 grain tips and went down to 100 grains. And when I moved to a lighter, faster bow I stuck with the 100 grain tips. I saw a pretty big difference going from 125 to 100. But I think that is because I changed arrow type at the same time. I went from Alum. with 125gr to Carbon with 100gr.

My father has been shooting bow since he was in his low teens and says that ever since he had the choice of a tip weight he has always used 100gr regardless of the arrow type.

I personally think it is all personal preference, just like deciding what Bow you will shoot. Shoot what feels right for you and everything else will work out.