Power, reliability, accuracy, very easy to maintain, inexpensive. As soon as I got the cosmolene off my paratrooper model (shorter barrel mostly), I was hitting my aim points and 100 and 200 yards, regularly, with open sights. Shot it so much the first few months, I put a rubber butt/recoil pad on it the second week. Took the twenty round box mag off when I found reliable thirty round banana mags to fit it. Get it dirty, don’t clean it regularly, it still shoots reliably. But I clean mine after every trip to the range ... part of the shooting ritual.