To clarify, im not referencing the width of the grip, im talking about the width of the slide and forward portion of the frame that are actually inside the holster in your pants. The width of the grip seems to have less impact on comfort since it's above the beltline.
I agree, and it's a good observation. I carry either an XDs, in 45 or a SP101 in .357. The grip has nothing to due with carry comfort IMO as the slide and frame width, or the cylinder width of a revolver are what actually makes your pants fit a little tighter. As a result of the thickness, the SP101 is much less comfortable to carry for me.
Now grip size DOES have a very real impact on how well you can conceal a gun.
However, when manufacturers bring a new carry gun to market, they typically emphasize the slide and frame thickness, as well as the widest point. The grip LENGTH is also emphasized as it can cause printing.
So your initial assertion that a narrower frame and slide will result it less "brick" like carry feel is correct, as that is what sits in the holster. The simple solution is to buy larger pants, a longer belt, and a good holster if you want to carry a thicker framed gun.
The grip length (and width) is why I went with the XDs. Manufacturers make their guns to fit the most people. My hands are of the extra large size, and as a result, many small guns don't work for me as the trigger reach is far to short for me to have any kind of good trigger control. The length is just long enough for me to wrap three fingers around the XD's, and have my pinky rapped around the bottom. However the trigger reach is far enough that even with a narrow grip, I am able to control the trigger and shoot the gun well.
I suspect grip width may be more important to heavier set folks who IWB carry, as it may rub them the wrong way. For thinner folks, grip width seems less important for IWB carry, IMO.
