I don't own a Kelly Dog but I think the Kelly Dog looks best when it fits in the middle (of thre three) holes. The CDC has four holes to adjust and I think it looks good in whichever hole happens to fit you. I wear mine in the smallest setting and I don't feel it changes the look of the bracelet.
I also read that the all-leather CDCs are bigger than the ones with metal, and some people who don't fit in regular CDCs can wear the all-leather ones.
I think it's best if you can actually try one on. Also there seems to be a difference in fit depending on the leather. My alligator CDC is the tightest, my lizard the best fitting, and Epsom the largest. The difference is tiny, but I can feel it. Each one also seems to stretch a little with wear, kind of molding to my wrist.
Also -- there is a discussion on the CDC thread about the size of the CDC for men. Someone was trying to get a bigger bracelet by buying the men's size online but it turned out to be the same as women's size. However there was some discussion about how this might be different next year, when the men's bracelets would have small and large sizes. So that would be a possibility, with more limited color/hardware (I have only seen black with PH).