The 91 will weigh the same as an 80. You will need all of the extra power if you want to climb out of a hover. Go with a 4 stroke, the power is more manageable and throttle response quicker. You will be happy with a Saito, ounce or two lighter than the Magnum. Magnums run ok but their workmanship doesn't even compare to Saito or OS. If you go with a Magnum, handpick it if possible. Check for excessive end play on the crank and smoothness of the throttle barrel operation.