They were one of the first broadheads I used when I started bow hunting. They worked well, flew like field points, killed deer. Never had a problem with one not opening if that is your concern.
I dont use them any longer, but thats because I like to try different broadheads, no reflection on the spitfires.
“There are two spiritual dangers in not owning a farm. One is the danger of supposing that breakfast comes from the grocery, and the other that heat comes from the furnace.”