From chatting with some fellow LAVAers it seems the Statechart module does not get much love. But my collegue has used it quite effectively on multiple RT projects, usually for implementing control.
So I have/can see the benefits and it's something that I have not dived into but I am keen to, one day.
So, whilst I have not much to add, I too am interested on others experiences. One of the downsides is that it's another module to purchase so not everyone has access to it.