When I started in law enforcement is when my experience with DA revolvers started. Back then ('64) we were allowed to carry .357 magnum revolvers and ammunition. The LE profession led me into PPC competition, which mandated .38 cal ammunition.
That environment focused my interest in .38-.357 caliber revolvers. Because I wanted maximum stout in the early years, before we were mandated to carry the issue S&W 66 - 4", I favored the N frames. My last personally owned duty revolver was a 27-2, which I still have.
Our departmental experience with the 66 was not very reliable. When the L frames came out, they looked to me to be the ideal compromise, sitting between the K and N frames. By this time I was far enough up in the rank structure to have some clout (assist powered by persistence). I got a great offer from Bill Davis for a straight across trade, our 66s in exchange for new 686-4"s. Great improvement in reliability over the 66s, they were the issue revolver until mandatory switch to semi-autos.
Inevitably I got an L fame of my own. I bought a no dash 586-6" with the tall post front sight to allow for a neck hold at 50 yards for PPC shooting. I also had that revolver completely customized for competition.
In my mind, perfection.
So my favorite revolver is the adjustable sight L frame. I have always thought that S&W nailed it in a .38/.357 size revolver.
Since one poster went off-course to rave about the 6906, I will too. The 6906, with its double stack grip, fits my hand better than any other handgun, revolver or semi-automatic, that I have ever used. On our qualification course, using that pistol, I fired higher scores with tighter groups than I ever did with any revolver, despite it being smaller, lighter and with a shorter barrel.
In the semi-auto world, the 6906, in my opinion and experience, is the best. Another example of where S&W nailed it.