I have a set on my 4" L-frame. My fingers don't line up with the grooves in grooved grips, and I prefer the look of wood, and the JM grips feel pretty good. I like them for shooting .38spls, but recoil is pretty harsh when used with full power .357magnums. I've heard that complaint from others as well, and even JM himself admits he has trouble with them when the power factor goes too high (I recall his limit is a PF of 200).
They're pretty long, too, which helps the weak hand grip, but, because of this, I don't think they're very suited for concealed carry. Of course, a 4" L-frame wouldn't be the easiest thing to conceal, either
Of course, they're going to feel different for everyone, so the only way to see if yo like them is to try them. Personally, I ordered some Ahrends to see if they handle recoil better.