The difference is personal preference. DAO would require a diliberate cycling of the trigger each time one wanted the gun to go bang. Less likihood of ND/AD by some peoples assessment. I personally prefer to keep my options as open as I can and prefer DA/SA mostly because I'm not a fn of the "cocked and locked" thing. Open options for me is also streamlining and an extra step to drop the safety just doesn't fit my definition.

Neither one is any better than the other in most regards. It's just a feature. Do you like/want it in the handgun you are choosing? Why do you want it? Are you comfortable using your firearm with a particular action? Some people, for whatever reason, want the heavy 10-ish pound pull for every shot. I practice DA shots when I go to the range as I figure I may not always get an opportunity to cock the hammer before taking my shot. However, I personally like having my follow-up shots sent down range with a 4-ish pound pull.

Personal preference is all. SAO, DAO, SA/DA and all the variants of them. If it's something you like AND want, by all means do it. You have those choices in this country. Have fun with your decision.

Are you talking revolver or semi-auto or just in general?

For example...My XD guns are SAO...You rack the slide and the striker is in the ready position...as long as you have your hand on the grip and your finger on the trigger, you squeeze and she goes bang...When the slide cycles on it's own after each shot, it re-cocks the striker for the next shot. All you gotta do is pull the trigger...Trigger pull is very light

Now some semi-autos have the option with a hammer to manually cock it and shoot first shot in SA...or first trigger pull is DA and all others are SA. if the hammer is back it works as SA if the hammer is not back it works as DA, but I still believe you have to rack the slide to chamber a round..

Revolvers can be one or the other or both...Big part depends on what you are comfortable with and if it is a defensive gun or a target gun or what..As stated before DA is usually a much heavier pull and SA tends to be much lighter...

I carry a Beretta 96 CCW and it is a DASA. I like the readiness of the first shot double action, the trigger pull also cocks the hammer and following shots in the SA mode where the slide's cycling cocks the hammer. I had a 96 Centurion DAO police turn in and it shot well, but was not as good a fit for me as the 96 FS. Think of a DAO like a double action revolver where every pull of the trigger is long and cocks the hammer to fire the round. I carry my Beretta with the decocker/safety off. After I load the weapon, I decock the hammer and holste the pistol. As a Beretta requires the trigger to be fully to the rear to release the firing pin block, I feel totally comfortable and safe. The number one safety on any pistol is the operator. Always remember the 4 rules of handgun safety and follow them without fail:
The 1st Law of Gun Safety - The Gun Is Always Loaded!

The 2nd Law of Gun Safety - Never Point A Gun At Something You're Not Prepared To Destroy!

The 3rd Law of Gun Safety - Always Be Sure Of Your Target And What Is Behind It!

The 4th Law of Gun Safety - Keep Your Finger Off The Trigger Until Your Sights Are On The Target

Originally Posted by funkypunk97

OK I'm still a little confused on this topic.... I've read a lot of info on this but I cannot really find the answers I'm looking for as they work in the practical world.....
Why do I want or need one over the other? Is DAO better, is there really a big difference between DAO and DA/SA....
Is there a safety or benefit to one over the other?

SA (Single Action) = the trigger feels the same, always. The trigger pull is short, and can be pretty light.
DAO (Double-Action Only) = the trigger feels the same, always. The pull is usually long and relatively heavy. This is a useful option, for instance for a pocket-carry pistol.
DA/SA ("Traditional" Double Action) = in a semi-auto, the trigger feels long and heavy for your first shot, and then switches to relatively short and light for all subsequent shots. Some people find that the transition from DA first shot to SA subsequent shots negatively affects speed and accuracy. But in a revolver, you have the choice of DA or SA for each shot, at your option, and pay no transition penalty.