But referring specifically to The Hogwarts Express - yes the technology is amazing and yes it will be immaculately presented, but I assume it will be a simulated train journey with special/physical effects and movie references. Regardless of the technology, I don't know what they're really going to do that we haven't experienced before one way or another (i.e. in other dark rides or live-action mazes)
You couldn't fail to be impressed by Forbidden Journey and all the swooping about, and the same can already be said for the Gringotts coaster, because they are literally other-worldly experiences, unlike anything we have anywhere else. But I think the Hogwarts Express experience itself may require a bit more knowledge and indeed passion for the books and films as it really is a train ride where some odd things happen.
This is not to say that I don't think it will be the BEST TRAIN RIDE IN THE WORLD.