It's difficult to describe Wonderspaces. I'd call it a "clever and innovative synergy between creativity and technology" but that does little to illustrate what's at play here. The best I can say is... "if this comes to your city, go experience it yourself".
This is a question I'm asked often and one that we weigh continually in our work. There are no simple answers. As is often the case when weighing technology solutions. But this is a pretty fair article that compares the two relational DB technologies.