A lot will depend on the thrower, the wind, and the disc. There's a vid of Katchz throwing something like 45 degrees in a monster tailwind and going like 700'. For me it probably is closer to 15-20 degrees. For players with less power the trajectory will be lower as it's harder to keep the nose down. Most torque monkeys/strong armers and air bouncers are throwing with a negative trajectory and nose up, not good for distance.