When I scroll through the glider options in the kart selection, I find no difference in the gliders except a small acceleration/weight tradeoff. I recognize that this is probably due to the gliders having no effect on driving speed, but do some gliders fly faster than others?
Gliders give one of two boost, acceleration or speed.
Super glider, Waddle Wing, Plane, Wario Wing and Gold will increase your speed in air.
Flower, Peach Parasol, MKTV Parasol, Bowser Kite and Cloud will give better acceleration
Non give more stats then the other so the rest is just cosmetic. hope this helps.