Do you know of any successfully semantic RDF graph databases, I guess with OWL support? Because I personally don't. If not, it probably is rightfully too much an academic niche to be discussed in the article.
We are using Blazegraph and Neptune in production as well as Allegrograph. With Neptune, we tested scale by putting the entire dbpedia on one 4 core machine with 16G of ram. It handled 2.7 billion statements without any issues (we ran out of time with the test - sure it can handle more)