I think a drop track in the middle of a coaster sounds pretty thrilling to me. Especially because MOST people won't expect it at all from a roller coaster. There are not a lot of "drop coasters" in America, (that im aware of), and I think that will be the part that blows the GP away.
adding that to a coaster that has 4(?) launches, a backwards section, and elaborate themeing, will make this quite the popular ride. Likely the favorite Potter ride, and possible the best ride in UOR.