I teach all the NRA pistol classes - from basic to the most advanced. During the more advanced classes the focus is on speed and accuracy. Students have to draw from concealment, then shoot AND HIT the target center mass during the final firing sequence. Hits count. I am often questioned about small caliber guns for concealment. They are easy to hide, generally easy to draw and with practice just as effective as something larger.
Small handed people have trouble with larger pistols. The grips don’t fit their hand well. After they shoot about a thousand rounds through a small pistol doing draw from concealment and put holes center mass I for one would not mess with them while they are carrying a .22. They are just as deadly.
Additionally if anyone has ever shot someone with any concealed pistol and had that pistol “knock them down” - I would like to hear about it. Simple physics says that in order to knock an attacker off their feet the recoil from that pistol will either knock the shooter off their feet or at the least break a wrist or shoulder. Attackers don’t get knocked down...they fall from lack of blood or because they are so mortally wounded that their brain finally tells them to fall down.
Carry what you are comfortable shooting 50 rounds at a time with. Practice and practice some more so when the SHTF you don’t have to think about all the steps you have to take. You just have to make sure you are in the right defensively and let muscle memory make accurate shots.
My EDC alternates between an eight shot .22 magnum revolver snubby or a Bersa 32 acp. The second shot will be either a head shot or a bladder shot.