Hello. Count me in as a fan of the Model 64. Mine were all bought used but they were internally sound, correctly-timed and had smooth trigger-pulls.
This 3" came in the normal DA/SA spur hammer configuration. I labeled its hammer, put it away and fitted an S&W factory-bobbed hammer to that revolver. It makes a very nice concealed carry package and one that many find surprisingly easy to shoot well.
Likewise, this 4" RB was purchased used. It reportedly had been an issue-gun for some security company and has one of the smoothest actions of any of my revolvers. It had a few carry "dings" and "marks" but didn't appear to have been shot much. Where the hammer and trigger on the 3" gun were flash chromed by S&W, the hammer and trigger on this one is not, though the frame, cylinder and barrel are stainless steel. Though purchased "pre-owned", this is one of my favorite revolvers.
As luck would have it, a fellow in my area had another M64 4" HB for sale and I couldn't resist. As I frequently do, I labeled and stored the spur hammer that came on the gun and fitted an S&W bobbed hammer to it. I used this particular revolver for the revolver recertification as a state CHL instructor. It had a few dings, but careful work with fine sandpaper restored the revolver to pretty nice external shape. The interior was fine and the action, smooth. The stocks did require some sanding and refinishing. I've carried this one concealed a fair amount and feel quite adequately armed when using loads of my choosing such as Remington's 158-gr. LHP +P.
If one bobs the standard spur hammer, it will still be capable of both DA and SA-firing, though lowering a cocked, bobbed hammer is a bit risky in my opinion. The ones shown that were bobbed by S&W are not capable of being cocked. I believe that NYPD ordered revolvers with spurless hammers and capable of only double-action before they transitioned to autoloaders. I think that this configuration is sometimes called "NY-1".
Whether you opt to stick with the spur hammer (which can be rendered capable of DA-only fire if you like but still retain the spur for perhaps being secured in a strap-type holster or just looks) or go with a bobbed one, just depends on your personal preferences. I almost always shoot DA with these particular revolvers so I prefer the spurless DAO versions. Others will feel just the opposite. The question is what do
you prefer; you definitely
can have it your way without much trouble at all.
The guns do have fixed sights. In my experience, they are usually pretty well "on" at 15 to 25 yards with standard and +P ammo weighing 158-grs. I find that at 15 yards or so, standard pressure 158-gr. SWC's @ 800 to 850 ft/sec strike almost exactly the same point of aim as 158-gr. LHP's running around the 900 ft/sec mark. If you envision trying out load-after-varying-load in .38 Special, an adjustable sight model revolver might be a better choice. On the other hand, if you envision the gun as one for carry, knocking about the woods, a "car gun" or "house gun" that can generally be handled well with full-house loads from
either hand for quick and accurate repeat shots, the Model 64 might be a very viable choice. It depends primarily on what
you find important,
not me or other folks.
As has been noted, these K-frames can be shot nearly forever with .38 Specials and remain in very serviceable condition.
As mentioned previously, I trust the gun and the caliber (as much as I trust any handgun caliber commonly associated with self-protection) if I can choose the ammunition. I also find these revolvers in this caliber a heck of a lot of fun to shoot just to have fun...something that rates highly on my list of things to do. If the same holds true for you, you might be well-served with one of these "vanilla
just-a-38 revolvers". On the other hand, if you simply do not believe that the .38 Special has enough "stopping power", it might be better to pass. You know your own parameters better than anyone.
Should you buy the revolver and wind up not liking it, I strongly suspect that you can get you money back without too much trouble. That said, if you buy one of these "stainless Model 10's" and shoot it much at all, I think you may find yourself a fan.
There are certain handguns that are just special to me...and I suspect others. For me, some 1911's, most Hi Powers and some revolvers certainly are and the Model 64 is a favorite for sure.
If interested, here are some related observations on the Model 64's:
http://www.thehighroad.org/showthread.php?t=475608
http://www.thehighroad.org/showthread.php?t=405830
Best to you and yours and good luck.