I'm sorry if this has been made clear elsewhere but I wasn't seeing how you are suppose to gain altitude with this?

When I press up+shift the speed reduces, it doesn't seem to give me any perceivable height.

Also, it seems this glider is angled downwards more than the Reusable Glider, I seem to hit the ground muuuuch sooner with this glider then any of the others when i'm simply coasting forward.. Is there a way to fix this?