For some reason when they built the Tower of Terror in DCA, they went with a simplified version. Still a great attraction, but the queue isn't as impressive (Studio's Tower of Terror queue is one of the best anywhere IMO) and the ride doesn't roll forward out of the first shaft (the 5th dimension) like it does at the Studios. IMO the exterior is not as impressive either. They obviously had a tighter *budget* at DCA then they did at the Studios...
That's why I said it was dumbed down. I don't know if that was the right term, but it sounded good at the time.
If you had never been on the Studios version you would no doubt say it was an awesome "E-ticket" attraction... but having already ridden the Studios version, I had fun, but I had to wonder what the big wigs were thinking on that one.