I would say not very desirable unless you collect old police type guns. I have a 4" 64-5 DAO. It's a nice gun but I doubt they're going up much in value.
I've got the same revolver and it would serve perfectly as a defensive firearm, truck gun, etc. Collectability is low with them right now but they are one of the best deals going in firearms. Got mine for $200 last year, it is one of my favorites to shoot hands down.
My former agency "pushed" them. Did away with the menace of people cocking the hammers on their service revolvers. Unaware of any desirability or increase in value due to DAO mechanism.
The Model 64 with a spurless or bobbed hammer and DAO internals in a great carry gun. Have quite a few. Several NY-1, a Brinks trade-in, and a couple of uncertain origin. Reliable, rugged, and easy to shoot with 4" or 2" barrel.
EDIT: I have two, a 2" and 4" that came from the same former NYPD officer. Bought them a year or two ago. He texted me a few days ago to say that he found the old holster and would send them down to Charlotte. So, I'll start a separate thread about the reunited holsters and guns in a few days.
The NY-1 marked DAO model 64s have a good following, but at this point most of the others (probably authorized/issued because NYPD did) don't show much of a premium in value.
I have one, picked it up for around $300 a couple years ago, and it is very desirable to me! Had the cylinder machined for moon clips for fast ejection and reloads, makes a great carry/car/truck or just around the house or garage revolver. As for value, there are so many of them that for resale a standard 64 is probably worth more and always will be. They're cool though, you need one for sure!
I have a "few", DAO, da/sa, 2",4" NY-1's, a k frame, heavy barrel,SS, 38 special, whats not to like. Collectable? good guns, can be had for decent prices, NY-1's as stated above will bring a premium, dependent on your WANT!! Be Safe,
I have one, not agency marked, paid $385 last year. The hammer is spurless from the factory and cannot be cocked. If you like model 10s, you will like this model 64. If you prefer a SA/DA gun, replace the hammer.
An officer in my first department was the portly type who often pulled up his pants with his left hand on the sam browne and his right on his holstered model 64. Sitting in his Malibu partol car he noticed that the hammer was cocked. He took the gun out and it just went off accidently according to him, The bullet passed through the dash board, firewall, ricocheted off the hood and into the radiator while sitting at he gas pump. In service training on how to decock a revolver for the entire department. DAO is not always a bad thing.
I've got a 2" DAO model 64 I purchased from a retired NYPD officer. The bobbed hammer makes selecting a holster with a thumb brake a little difficult , but not impossible. While the DAO trigger isn't great, I should probably shoot it more to develop better double action trigger technique. to me the strength of DAO revolver is as a training gun for better trigger technique. The only folks who seem interested in buying a DAO K frame by me are folks you are into NYPD guns.
I do believe that a 4" DAO 64 would be a great service weapon for some one mandate to carry a .38 DAO revolver.
I bought one at the last gun show.
Came from the NYPD, and the double action has had a lot of work as it is so easy and quick to fire double action. Trigger pull is super light and cartridges fire easily!
Too heavy and large for me to carry concealed.
I broke the hammer nose on one of my 10HBs a few of years ago. When I went through the parts in my stash I found a hammer from a parts kit purchased maybe 15 years ago. Factory DAO hammer from a 2" K frame of some kind. Put it in the 10 until I could round up the parts for a repair. I repaired the original hammer but after shooting the unit with the DAO hammer (and loving it) it remains and the repair job is in a parts bag with the number of the gun until such time as I move the gun down the line. And as it is just about my favorite range gun, I suspect it will be some time before that happens.