On revolvers versus the semi auto in Law Enforcement, and this may sound very, very, very, very, cynical cost of the gun, cost of training folks to use the gun, and NOT what is the best is a major consideration.
Price a name brand 6 shot revolver and price a name brand semi auto, you will find the semi auto is a bit less. Price ammo for both and you also find the same result, price training a shooter and you will see most shooting is toward the semi. Price service, meaning smithing or parts and again revolver is higher. Why is not the point, just that the semi being more popular there is less demand hence less supply and then more basic cost.
Think about a Novice shooter as 98% of the Police Recruits are learning to shoot double action six shot 38 special or 357 Mag with recoil and think about the same with a novice shooter with a 9mm semi auto. Believe it or not the Semi is easier to train. And with the new DAK or LEM or what ever it is called on a semi, you have a very, very, slick and LIGHT long trigger pull with a semi.
On a revolver that kind of action or a "lightened trigger" due to the design of the gun can easily be a light primer strike and when you have an LEO agency with about 2000 to 3000 sworn that is a bunch of armorers working all of the time. Are there any revolver smiths still out there. Not many.
A word or two more on training. On the revolver all recoil is directed to the hand and wrist. On an auto the slide will diminsh or absord some of the recoil before it is transfered to the wrist.
Again, just more thoughts.
By the way, I personaly prefer the revolver at home and am required a SIG P226 in 9mm at work. Both are similar in action style for the first shot.