There are some really effective .22LR rounds....Stinger are good, CCI Velocitors are hot, and I hear QuickShocks are awesome little rounds.
the debate over .22 being too little to carry will go on forever but one things for sure, I wouldn't want one pointed at MY head...it gets my respect.
My P3AT was a bigger round but all I could hit was COM at 10 yards or less. With my Taurus PT-22, I had one extra round and it was so accurate, I could AIM if I had to and KNEW I could hit it. Never felt under-gunned