In a department I used to belong to we had them and they took up good space on the engine. If you have an engine compartment fire on a vehicle, you eventually have to get the hood open anyway. If you have a fire in the wall we open the wall up to make sure its out......In my experience I have not come across anytime it was worth taking the time to hook it up and use it.
We used ours a couple weeks ago to stick through the rubble of a house fire to put out a hot spot in the basement. The three story house was a total loss and collapsed upon it's self; no way was it safe to put a man in the basement, so we used our penetrating nozzle.