I have owned all of the ones you are asking about.
J-frames are neat, but are really not as small as many seem to think. They are "organically shaped" with more curves and fewer straight lines, but they are also longer front to rear than a number of semi-autos, which may result in the handgun "peeking" out of your front pocket.
My Kahr PM9 is a bit more "blocky" but sits down in the pocket and does not stick out.
Actually, both my Kahr P45 and my 3" 1911, pocket carried, are easily as concealable as a j-frame.
FWIW, after owning 6 J-frames over the years, I do not own one today. Not to say that I will never own another...