I don't know. I really can't get enough keys for all the specialized buildings without Dr Vu. If it asks for 48 of one thing and 48 of another, that is what you use the button asking the architect to draw up new plans for. In 30 min you have a much more reasonable rebuild. I think it got tired of me always asking for new plans because, after a while, they were all really simple. I had by beach loaded with items in one week. Not sure where I will fit the marina. There is real merit to Dr. Vu. However, I really don't use more than the first one, the meteor. I get two keys for each disaster, after one upgrade, and the rebuilds are easy, though listed as medium. I have looked at the return on others. I don't want to have to rebuild 5 buildings and get 1 or 2 keys when I can rebuild 3 buildings and get two keys. I'm sticking with this upgrade.