First, I would argue that a 1911 is a spectacularly bad platform for a self defense arm (for many reason), and making the comparison isn't terribly useful.
Second, the single action on a typical revolver is significantly shorter and lighter than even a well-tuned 1911. It's not unusual to find revolvers with single actions in the 2lb to 2-1/2lb range, with absolutely zero travel. Even the most rabid 1911 apologist would be uncomfortable with that kind of trigger for self defense use.
The difference between a double action and single action on a revolver is far greater than that of a DA/SA auto: a revolver DA is usually in excess of 10lbs, many times 12 lbs, and single actions are usually under 3lbs with no creep. Compare that to a really good DA/SA auto, where the DA is usually less than 10 lbs and the SA perhaps half of that, with tons of creep.
Out of curiosity I checked the DA and SA triggers on some of my firearms:
- Ruger P95
- Sig P220
- S&W Mod 15
- S&W 686+
Next I took the autoloaders above to the range along with a Kimber 1911. I paid close attention to the action and Mr. Cunningham is right -- the triggers really are pretty creepy.