I think they are more or less a niche market and generally, dont do things better than other guns in the caliber.
I think a lot of the time too, its one of those things that sounds like a good idea, and just doesnt play out that way in reality. Kind of like having a rifle and handgun in the same caliber.
"Convertible" guns sound like a good idea, but in reality, you usually end up with the set up you like and use, and the convertible items end up in a box, never to be used again, and just taking up space.
Ive had a few in the past and currently have two, both S&W's, a 1917 and a 625. Great guns, but so are my other revolvers in more traditional revolver calibers.