Im a skinny guy and wear form fitting clothes and im still able to comfortably conceal a full size gun. I dont carry anything smaller then a G19 IWB.
I dont trust little calibers and dont carry anything under a 9mm. Small 380 semi autos i find to be unreliable and to small to fit in my hands. I have a m36 snubby in 38spl that i carry only when i have to really hide a gun. Like when its a formal occasion where i cant just use a iwb holster and a full size gun. In this case something is better then nothing, the revolver is reliable and the caliber in +p hp is enough to at least make someone think again
I'm shocked that a Ruger tech thinks it is okay for the LCP to "jam" 5 times out of 400 rounds. Any gun carried for self defense must run 100% or be set aside for something else. One of those five malfunctions may happen during a deadly encounter and as has been said, there is no second place winner in a gunfight.
I now carry my Shield .40 with Crimson Trace laser every day in the concealed right pocket of my Blackhawk pants and Blackhawk shorts. Also carry an extra mag too. Works for both cold and warm weather carry.
If summer ever comes to Michigan, I will be happy with my 442 in my pocket or belly band and a speed loader/speed strips. If I have to wear "clothes" my 9C conceals nicely. Like I say, that assumes summer will ever come.