if the carbon arrows you shoot have the same shaft diameter as an aluminuim arrow, then you should go with the aluminium. if they are regular carbons that are smaller than aluminium arrows in shaft diameter, then go with the carbon insert. if you shoot aluminium arrows get the aluminium insert

i have a new Quickshot Deluxe model with the B2. i have no fletching wrinkling or anything different from the prong style rest i had before the biscuit and have put over 100 shots through mine. [knock on wood] hopefully things stay the same.