Like the OP, I have many J-frame revolvers. Many revolvers in general actually, and use several of them for self-defense purposes. If you subscribe to the theory which I do, in that three handguns of the same "family" can serve all defensive needs, then a sound J-frame would be one of those three if the family is revolvers.
All CCW guns are a compromise, as portable insurance. If you knew trouble was coming you would arm yourself with a shoulder gun. If you were a high-risk individual, you might wisely select a larger more capable handgun. But the J frame is entirely suitable as a CCW for the vast majority of situations, which the vast majority of people find themselves. I never feel underarmed when carrying a J frame - or any revolver - when appropriate.
Having said that, there is much to recommend the Glock 42. Like the OP, I also have one. If my 3-handgun family were Glock pistols, the G42 would be one of them. It is thinner than a revolver to make carry easier, holds a few more rounds, and is more practically accurate in most hands. You can easily add high visibility and/or tritium sights to the G42 as an accuracy and speed enhancement... with the revolver you get what you get.
While the .38 Special can be had in a few somewhat more powerful loads than the .380 - and with heavier bullets - unless you are shooting a steel J-frame, they are not conducive to accurate shooting. My chronograph gives the Federal .380 99 grain HST load 1030 fps out of the G42 for 235 ft lbs of energy. The popular Speer .38 Special 135 grain GDHP load chronos 855 fps out of my Model 36, for 220 ft lbs of energy, That's not enough difference, to make a difference.
If you carry a reload, the G42 magazine is more user friendly for carry than a cylindrical speedloader. But the speedstrip device for revolvers is very unobtrusive in a pocket. While one can practice can get pretty good with revolver speed loading, a pistol magazine will always be faster and require less practice and effort.
Finally, it is insanely easy to attach a Streamlight TLR-6 mini-weaponlight to the G42, giving you a low-light capability should your circumstances require it. Indeed, when traveling, your CCW generally becomes your only gun, including on the nightstand. The small profile and light weight of the TLR-6 allows you to easily carry the G42 with it concealed, in the same manner as always.
Much is made of pants pocket carry.... too much in my opinion. I rarely pants pocket carry even in the sweltering heat and humidity of the summer. On the other hand, I don't walk around bare-chested or in a "wife-beater" tank top, either. A t-shirt easily covers either a J-frame or G42 CCW in an IWB holster. I find revolvers a poor choice for pants pocket carry in the rare times that I do - the cylinder bulge is too thick, and anything much over 10-12 1/2 ounces loaded is too heavy in the pocket of lightweight summer shorts.
Winter coat pocket carry, on the other hand, is quite valid, when you are bundled up and a holstered handgun is difficult to access quickly or discreetly. Here the "hammerless" J-frame is superior in terms of safety, snag-resistance in drawing, and the ability to fire from within the pocket.
Since the grip angle and trigger press of the J-frame and G42 are more similar than most other revolver/pistol pairings, I would practice with both, and select the one that is best for the given circumstances at hand.
