If You lived in another area the cops would all be carrying 9mm. Change to .40 if you want, but don't kid yourself it's because its' been proven to be the best calibre. All the major calibres have the same stopping power to within a few percent. Your speed and accuracy with a round that suits you, will far outweigh any 'advantage' of calibre. Besides what is the advantage of standardising? You planning on going on a wagon train or something?
qjs