Well, I fed my mbuna tank some of the sample food John brought to the meeting last night and they did indeed devour it.
One thing I noticed though, the owner/developer claims it doesn't cloud the water but it did temporarily cloud my 190g until the filters cleared it up overnight.
I still would use the food, but I would not crumble it like so many reviews stated in the links I read. I think crumbling it caused the cloudiness.