W.E.G., I must respectfully disagree with the liability angle. Some PD admins certainly do see DAO as a lesser-liability thing, but liability is not the "only" reason to choose DAO.
I work for a PD that allows both DA/SA and DAK (a form of DAO) SIG pistols, and I chose DAK for myself, voting with my wallet, as we must buy our own. (Other pistols are also allowed, de-cockers and the hybrids such as Glock, S&W M&P, and XD.) The DAK was embraced first by the narc raid team guys, the best shooters, as a whole, within our agency. Believe me, these top shooters, and I, a less-than-top, but certainly better-than-average shooter, did NOT choose DAK for liability, but purely for performance. If a new future chief ever decides to allows us to revert to the older policy, that included the use of 1911 pistols for on-duty use, I won't switch back.
Liability has NOTHING to do with why I choose to use a form of DAK. I choose to use this system, and I am no Miculek.
I was actually a bit of a rebel, in 2004, when I started using DAK, because there were firearm instructor supervisors who refused to allow us to qual with DAK SIGs; policy merely stated SIG P229, but these supervisors interpreted it to mean only the original DA/SA version. The narc raid guys qual under their own supervisors, so they did not have to deal with the same range instructor supervisors I do. In 2007, the firearms policy was amended to specifically allow DAK, so now I can qual any time, without having to avoid any supervisors. (Our training/qual range runs 24 hours a day, five days a week; we are a BIG agency.)
DAK is not the only DAO I use, or have used. I loved my S&W Model 3953, which is now with a dear friend for as long as she wants to keep it. When I need a micro-hideout pistol, I have a wonderful Seecamp LWS-32. DAO can indeed be a choice that is not based on liability.