Don't be put off by the chest thumping. It is a legitimate question if you take the approach that any gun in your house could be pressed into service in a pinch.
I only own two handguns (I'm not rich). My SR9c which is 9mm, and an SR22 in 22lr. If I am downstairs, and I can't get to my 9mm, I will find myself glad I gave this topic some passing thought when the 22 is the only thing I can get my hands on.
That said, when I looked into it, those with meaningful opinions seemed to come down on the same side as those here.
A) Reliability, first and foremost because changes in performance between 22 rounds is marginal.
B) Higher Velocity
C) Round Nose over Hollow Point
The last was my biggest question, and the consensus seemed to be that expansion was not worth the loss in penetration.
And even if it doesn't stop them, if I can put a half dozen or so rounds in someone before I'm forced to duke it out, I think my chances of not taking a butt whooping have significantly improved :lol: