You've flown a Sickle? How much is a foam cutter? A sickle weighs under 3 lbs, so thrust to weight ratios of over 2:1 are common. The performance is spectacular. The wing weighs slightly more than a foam wing, but I can make 10 of them in a few hours for $15-$20 in materials and I don't need to cut foam. As for dark colored coro, unless it's over 85 degress you have nothing to worry about. Over 85-90 degress and the coro will get soft if left in direct sun for awhile. It happened to me once, in 100 degree weather, after 30 min. Solution? If it's hot, don't leave it in direct sun. Good advice for any model.