Many calibers come and go but the .22LR lives on; why look elsewhere?
I hear those .17 rounds are awsome but how can you beat the reliabilty and availablity of .22LR?
Also by the time you move up to .223 the weight goes up significantly and it blows apart small game.
Yes .223 has more stopping power but if you shot at someone in defense with a 10/22 with a large mag you can keep them pinned down a bit.
There are certain .22LR guns out there that can shoot .22 short and long. Some revolvers convert to .22 mag; I've always wanted a single shot that converts from .22LR to .22 mag.