This was used at a scenario event at sc village last year. I believe the underlying marker is a BT. It was intended to look like a ripper from Gears of War. He ran a remote line I believe. He used custom foam latex. I prefer to use autocockers and automags with gravity hoppers for scenario events. Keeps it simple.
The last few scenario games at sc village have involved a pretty good mix of all types of markers. I cannot say that one type stood out more than another.