I've loaded the full Freebase dump into Cayley one year and something ago (Freebase is probably already big-sized). It took around one week on a pretty beefy machine, the problem being mainly the way the data was structured in the dump.

But after the import, it worked pretty well without issues and with decent performances. With decent meaning: not good for a Front End, good enough for running analysis in a back-end using a little bit of caching.