The more offset you use the more rotation you'll impart to the shaft and the more stability you'll gain, but it comes at the price of more drag, less speed and generally more noise. The amount of offset used to be limited by the arrow shaft diameter and the spacing of your rest prongs so that you could get the vanes through the rest without contact. With shorter vanes like the Blazers and the new fall-away or shoot through rests that isn't as critical. Personally, if I was shooting a fall away I'd go with a more aggressive offset and with a shoot through (Whisker Biscuit) I'd go less aggressive due to the vanes dragging harder when they hit the bristles.