"First - you MUST buy the power functions to go with this set. Without it, it's a fine build but you'll lose out of the motorized elevator (much better than hand-turning).
Regarding the elevator drop, there's a bit of a danger of getting out of sync with the Powered Up app. The app decides when it's pulled the elevator car to the top of the tower, so if it's too short, too bad, and if it's too high, it'll activate the drop of the elevator car before you execute the command. It is not an error in my building, I'm convinced after all sorts of troubleshooting, but in any event, you can get out and back in to Powered Up and it'll work fine.
My only other complaint is that one of two of the black roof sections are connected to the structure by the most minimal number of bricks, so you may find it frustrating to get everything just right and not trigger a collapse of the roof section.
All of which sounds like I didn't enjoy the set, but I really did. The little touches all over the set are delightful, the build (other than the final two tower sections) is fresh and not repetitive, and it's a hugely entertaining structure all around."