I've never been a fan of the smaller NAAs. They just don't fit my hand well enough to be accurate. However, a couple of years ago I picked up one of the NAA Black Widows. The larger magnum frame, two inch heavy barrel, larger grips and enhanced sights make this an "always gun" for me. Regardless of whatever else I may have on me, its always in my pocket. About the same weight as a pocket knife and very accurate. Mine is the .22 magnum/.22 long rifle.
Back at the start of this summer, I was working outside and heard my dog barking. I went to investigate and found about a 3 and a half foot copperhead coiled up and striking at her. The .22 magnum made short work of the threat.
Side Note: I purchased two of these in one day. I bought the first Black Widow and when I walked in the house with it, my wife said "I really like that." A few minutes later she said again, "I really like that." I went back to town and bought me one. It is also her "always gun."