The differences between custom buildings are big as well, with some being very minimal in terms of actually being able to make things that are really creative. My favorite systems involve things like real physics for the pieces, along with the ability to move columns and such with fine positioning to create your own designs more fully. The more common system is based on blocks, with set positioning. Which works, but just isn't as much fun for those who really want to create something truly custom. It is, however, easier for more people to create their own places. I don't believe this is a huge focus here atm, but who knows. Eventually, maybe, we will get something like this added in.