I would have to say mystery mine opening year. We were going to a wedding, and went to Dollywood on the way there. All the brochure said was "vertical drop". I wasnt really expecting much, so I get on, it goes into tunnel, then stops and I look up. It's is a lot different experience than vertical on TTD, the only ever truly "vertical" coaster I have gone on. You are almost stopped on top before dropping, and the train is much much smaller.