Fly = flap flap over a building
there are basically four types of mounts (excluding the different mounts themselves)
Regular ground mount: 60% land speed bonus
epic ground mount: 100% land speed bonus
Regular flying mount: 60% land and air speed bonus
Epic Flying mount: 100% land and 280% air speed bonus.
So ya, my fantasy character is zipping (slowly) around the skys, flying over buildings, and it's great