Coming in a bit late on this but here is my take on this.
Myself,I have never been able to warm up to IWB mode of concealed carrying.
If you are upright it's mostly comfortable but if you are getting in and out of a small econo car or having to sit a lot not so much.
So I much prefer front pocket carry.
Again this is concealed carrying I am talking about coming from a state that concealed means concealed!!
The four guns I have the most experience with in this mode of carry is an older J frame S&W model 37 Airweight,a Kahr PM9,A Ruger LCP,and a Diamondback 380,and a Kel-Tec P32.
The J frame M 37 is certainly light enough but since it is about an inch in overall length than the other pistols mentioned it has the most annoying tendency of wanting to constanly peaks it's butt handle out of your pocket.
This has happened to me in Wrangler jeans,nice work slacks,and some other slacks.
While wearing the comfortable but rather frumpy looking "relaxed fit jeans" there is no issue with this problem with these types of jeans I have tried which are generally Sam's Club brand.
The other pistols mentioned due to their overall shorter length,as well as less width, do not at all peak out of the pocket.
To the J frames credit even in tight jeans I find it is a tad faster to draw because the butt handle is somewhat superior ergonomically over the other pistols I mentioned and you can get a firm grip on that little model 37's butt handle and easily spring it forth for serious duty.
The other pistols are not that much slower really while being retained in their made for the pistols leather pocket holsters,but one must understand when wearing America's universally loved blue jeans that over a period and a short few washings and dryings they can get fairly tight if they are your normal fitted jeans.
With that in mind please also understand because of work constraints as well as general appearance a lot of people who use IWB holsters need one that allows the shirt to be tucked in.
From what I have seen the actual time to draw from a tucked in IWB holster and a pocket holster is not that much difference in time really and with loose slacks maybe the pocket holstered guns are actually faster on the draw.
Not sure even if the quick draw scenario is of the utmost importance in the over all scheme of things for most concealed carry situations.
That's not to say during one situation or another that would not be the case though.
Lastly,and this is just me commenting here,I have never been able to shoot a snub J frame anywhere near as accurate as I can the other pistols I listed.
So I carry the semi auto's I mentioned in a leather pocket holster fully concealed and am happy with what I have.