Personally I look at it like this:
Am I willing to get in a gun battle with this gun?
The smallest I will carry is a J Frame, and very, very rarely is that a primary gun.
I had a Walther TPH that I really wanted to like, but it was simply not reliable.
I have ZERO desire to stake my life against an armed adversary with a derringer of any caliber.
I really don't even carry my beloved J-frame that much any more, opting for a Glock 43 or Glock 26.
Any gun is better than no gun. But if you're going armed, why not go well armed?
Derringer = non-starter to me.
