I'm the creator of :BaseKB, the first usable conversion of Freebase to RDF.
There are key integrity problems in the Freebase quad dump that make it hard to get fully correct results from the quad dump. :BaseKB reconstructs the key structure of Freebase so that the unique name assumption holds. This is important, because the ability to write simple SPARQL queries that work like SQL queries depends on this.
Right now, :BaseKB exists in two editions. There's a free edition that consists of 120 million facts about 4 million topics (the ones from Wikipedia) and there's a "Pro" edition that contains everything.
As for the performance issues brought up by Phillip Kendall, I can say that it's mostly a matter of having enough RAM. With 24GB of RAM I can load the free edition into a triple store in an hour. Some queries take longer than I like, but overall query performance is good.
Anyone who wants to use the "Pro" edition is going to need unusually powerful hardware and will spend a good deal of effort getting their toolchain to work. I'm working with partners right now to deliver "Pro" to users in a satisfactory way.