A HIT with a .22LR is infinitely better than a MISS with a .44 magnum!
I guess that's all there is to say as far as shot placement is concerned. Don't know whether that's familiar, but even the mossad used the .22, and not only for assassination weapons (which is a completely different matter), but also for its flight security agents: http://www.tactical-life.com/online/...mossad-22-lrs/
From the "European" point of view, .22lr IS definitely suitable for SD. We have far less guns around here in general, so it is also quite unlikely that the common housebreaker comes with a gun. Alas, in the last years the probability of facing a guy coming at you with a knife or an iron rod in your own living room hast somewhat increased, modestly spoken. And for THOSE incidents, a .22 is still sufficient (carrying a gun outside the own premises is anyway restricted to very few specially licensed people. And the BGs of course who don't abide the laws...)