I have Models 13/65, 10/64, 14, 15/67and 19/66.
The light barrel of the Model 15/67 mates perfectly with the .38 Special cartridge. Easy toting, smooth handling and great shooting.
(There was a special order run of 38 Special-chambered “Model 66” called the Model 68, too. The 68 had a 6” heavier barrel and ejector rod shroud of the 66 rather than the thinner profile/no shroud 67 barrel. I think these were CHP-LAPD guns.)
revolverguy.com
Of course the 13/65 and 19/66 earn the versatility nod with the option to shoot .357 Magnums and different barrel lengths from a 2.5” round-butt to 6” duty/hunting/target guns. IMHO, this dual-caliber ability and wider variety of options gives the 19/66 a prominent position in the halls of all-time great revolvers.
I don’t shoot many Magnums through my K frames, only because I don’t want to add any extra wear on my out of production revolvers with magnum loads. (I have an L frame and GP-100 for those.) I stick almost exclusively with .38’s, but lead-bullet mid-range .357’s will occasionally head down the tube.
For me, the 14/15-67 and the .38 Special are the cats meow.
For .357 versatility, the 19/66 are excellent guns, too.
Stay safe.