If you see the gust comming you should let the main or traveler out so you will be ready when it gets to you. If you are letting the sails out right when the gust is hiting you that would be good. If you wait until the gust hits you to let the sail out it is too late and you just pop up and don't get the forward speed. The best sailors can really read the wind and can time the sheeting to the wind pressure.