Personally, I look at the NAA .22LR/MAG derringers as basically being a last-ditch, "Onion Field" hideout weapon. Not so sure I'd go with the .22Short, though, although I'd not be surprised if some folks like it because it's a "neat" watch fob gun.
If anyone doesn't already know, you can find some NAA velocity testing at their website:
https://northamericanarms.com/ballistics/
I have an older .22LR, a newer .22MAG with the shortest barrel length, and a Black Widow with both LR and MAG cylinders. I wanted the BW for the 2" barrel length, some actual sights, and to take advantage of the then-new GDHP load (although I also picked up a couple of the Hornady FTX loads, since they were available at the time, too). I thought of the BW as being more or less a smaller and thinner type of "kit gun".
Here's a commercial "test" of the BW using the .22MAG GDHP load in bare gel and denim.
If anyone is interested, here's some independent lab testing of some NAA guns Other links at bottom of first page.
https://northamericanarms.com/testing/#1462642032281-fc668c62-551e
When I tried some standard Winchester .22 MAG, along with the GDHP and one of the FTX MAG loads, I was able to get some pretty decent accuracy out to 10yds, no doubt due to the larger grip and some 3-dot sights. Interestingly, the best accuracy came from using the LR cylinder and Stingers. That combo surprisingly made my BW into a tackdriver. Naturally, running the various NAA's through one of the usual "qual" courses meant keeping the distances under 11yds, and LOTS of time reloading.
I still look at the NAA guns as being a couple of ladder rungs below one of my LCP's, and I look at those as being at the bottom of the "minimally adequate" threshold. Not everyone may be familiar with working a SA revolver under even moderate range "stress", let alone a
really diminutive SA revolver. Better than no gun? Arguably ... probably. Capable of producing lethal GSW's? Yes, still a firearm.
Then again, I remember when the old High Standard DAO 2-shot derringers were popular for secondary weapons, in both LR and MAG. I remember when you could occasionally learn of an agency who bought them and offered them for officers, too.
Last ditch, close range last chance weapon. Pretty unobtrusive hideout weapon that could be discreetly carried. Easier to shoot in one respect, being DAO (albeit with a long and hard trigger pull), but also with only 2 rounds.
I have a friend (another retired peace officer and former firearms trainer) who usually carried 2-3 guns at the same time as retirement weapons. His "3rd" gun is often a Walther TPH .22LR, a LCP, a S&W .22MAG kit gun ... or a .22LR NAA.
Personally, I don't envision the limited "role" of carrying a NAA as being a gun that's going to be presented for potential threats to "see". I see it as one that's going to make noise when a threat is going to be wondering what's making that noise.
I know a retired agency Rangemaster who said he sometimes drops a 2-shot derringer into a pocket in some circumstances where he may not be carrying a centerfire retirement CCW. He describes it being something that would be employed really close, meaning the threat probably would think it was a punch to a sensitive anatomical spot being delivered ... but accompanied with a loud noise.
Hey, lots of folks, even experienced folks, can have their own opinions. It only has to work for them.