Data Center Design Questions

We are looking at possibly building a new Data Center and I have several questions

1)Do you have a “drop ceiling” in your Data Center or is it “open” to the “ceiling deck above’?

2) Why do you like or dislike the way yours is designed?

3) Do you supply your power from under the floor or from overhead?

4) Do you supply your Copper / Fiber cabling from under the floor or overhead?

5) If you could do it all over again, what would you change?