I believe I was told once that the 8 petals open up faster which dosent necessarily open up the pattern as much as u think. It does open up a little but it uniforms the pattern! Ive shot them.for years with great results!
I agree with the scrunching comment. Went back to 4 petal pattern and shoot the same pattern land on the ground at the same distance from me after fired. Loaded some powder got hung up when I tore them apart there was some pedals folded in and shot was in-between the wad and hull on the 8 petal. Just my experience with them. Downrange makes the best wads out there in my opinion. Just didn't see any advantage in the 8 petal.
Put the wads in the dryer for 4 or 5 minutes. The heat relaxes the petals and opens them up so the go on to the tool easily. I have been shooting them for 20 years and they work great. DON'T LEAVE THEM IN THE DRYER OTHERWISE YOU WILL FIND ONE IN YOUR SHORTS.