Unless I have my hand on the pocket gun, I'm faster drawing my G19 (wouldn't matter if it were any bigger or smaller) from my usual IWB holster in concealment, than my pocket gun. So, what I have is better for muggings, or active shooters.
For reference, I can draw, from concealment and fire a well placed shot at 7 yards in about 1.25 seconds. For my pocket holster, I'm looking at over 2 seconds. Of course, if I'm able to have my hand on the pocket gun (something I can't do normally with my waistband gun) it drops to less than a second. But the only time I'll have my hand on my pocket gun is if I perceive something might happen. A mugging is going to happen usually when you don't perceive it.
Small 9's are only a little bit bigger than .380's anymore. I'll take one of those over a .380 any day of the week, though my pocket gun is an LCR loaded with .38 +P.