I had an opportunity to actually use a couple of Halon portable extinguishers on a training prop fire many years ago and the results were amazing!!!
The prop consisted of a six foot high block wall approximately ten feet wide. There were three sections of rain gutter mounted on the wall so the fuel would cascade down one piece, fall into the second piece going back across the wall, then into the third piece crossed back again, then onto the concrete pad. They placed a can of diesel fuel on the wall and allowed it to run through the gutters and onto the concrete, made for a nice, hot, running fire.
Two very experienced firefighters (me being one) with two CO2 extinguishers just managed to extinguish it before the extinguishers ran out. Second time with two dry chems, same result. Third time, with two Halon extinguishers the exinguishment was all most instantaneous, we hit the base of the fire on the floor and it put the entire fire out. It was absolutely amazing!!!
The only problem with Halon is the whole environmental thing with ozone depletion. Due to EPA regulations commercial Halon systems are almost non existent anymore.
2004 Dodge Ram 2500 Club Cab 4x4 CTD
2007 Sunline Solaris T-276-SR: Misty Blue/Cherry
2001 Dodge Ram 1500 Reg Cab 4x4 OFF-ROAD