Just noticed that ckolivas commited a changeset a few hours ago with an update to the bitfury driver. Re-compiling from source, with those changes, made a difference in the numbers I was seeing in cgminer. Cgminer reported hash rate went from around 1.7-1.8Gh/s to around 2.2 - 2.5Gh/s.
Good find.
I updated my cgminer and the reported hash rate did the same.
I am running both erupters and blue fury's on the same raspberry pi with no hoops to deal with. Just plug and play.
Unfortunately, total hash "appears" less than when I put the blue fury on its own machine.
edit: I did not wait long enough for things to stabalize. I am now seeing the same total hash using just the pi with both erupters and the blue fury as I did with the blue fury on its own machine running bfg.