The one employee of my lfs that I trust put a BGK in her cichlid tank. Someone special ordered the BGK and then must have changed his mind and never came to get it. They were keeping it in a 20gallon (it was still small). After a while of no one buying it she decided it needed to go into a bigger tank and decided to try it in her cichlid tank. She told me that its doing just fine, she just gave it a few different caves to hide in and the cichlid haven't bothered it.
-just one success story, I'm not trying to tell you to try it, would hate to think of a BGK getting ripped up.