I don't think they're exceptionally rare, but you don't run into them every day.
I have a 60-15 3" .357 that goes on hikes and on the river with me, and a .38 model 36 (square butt, no-dash) that's a little rough finish-wise, but I couldn't just leave on the shelf homeless like that, right? Like JimC said, it's a nice handling revolver. I shoot it much better than my snubbies.