Our Special Unit is our brush unit. Every department in our county, except 2 department, either have a brush or a special unit. They may not run very many calls but thye come in handy when they are needed.
I can't speak for all but in our area it's not really an option. Some of the roads aren't big enough for our engine. Granted the mini pumper can go most everywhere that the brush truck can but your only putting to people in the truck.