If you are hunting with these arrows, weight is important to an extent. Ten grs per pound of draw weight is considered the norm. If you only shoot 3D and targets weight matters little, actually lighter arrows are probably better because they fly flatter.
My hunting bows are in the 55# range and I shoot arrows from 550gr to 650gr normally but have hardwood shoot arrows that are pushing 700gr. At hunting distances(15yds to 20yds) I see very little difference in their flight. Any farther than that the heavier the arrow the faster they fall.
I don't shoot targets. My target butt is a large foam block and I will pick a spot(a blemish, hole, etc.) on that block to shoot at. I also don't shoot groups. I prefer one arrow at a time, as long as I am in full archery shape; been shooting on a regular basis. When you hunt you generally only get one shot and I want that arrow to go where I look. For me, if I shoot groups the other arrows in the target draw my attention and take away from my concentration.