Lloyd,
While it is probably true that a person with a double action who is practiced and skilled at reloading with a speed loader might leave you in the dust, the fact of the matter is that the vast majority of crooks are hapless when it comes to being good shots or being skilled in fast reloading, both with double actions and semies.
It constantly amazes me that both police officers and crooks, being people who must literally live or die by the gun, are on average such poor shots and so poorly skilled in general with their handguns.
When I lived in Memphis, we would have an annual invitational shoot, between the Memphis Police (using double action revolvers) and the Single Action shooters (using single actions), shooting six round strings at metal silouttes, at about 25 yards.
The cowboys ALWAYS won.
You could tell when a cowboy was on the line, because you would hear this:
Bang-clink, Bang-clink, Bang-clink, Bang-clink, Bang-clink, Bang-clink.
You could tell when an officer was on the line, because you would hear this:
Bang-silence, Bang-clink, Bang-silence, Bang-silence, Bang-clink, Bang-clink.
My uncle in law was a police officer on Long Island in New York, in the 1960s and 1970s. This was back when they carried revolvers. He told me that in 23 years on the force, he had never drawn his gun once. And, that the only time he ever fired it was about a week before the annual qualification, when he would fire about two boxes at the range the day before, to get ready for it.
Just some things to think about. Not trying to slam all police officers, as I am sure that many of them are excellent shots.
Manny