I've owned both, but sold the 43s for a pair of Sig Sauer P365s. I had some issues with the Sigs and sold them, replaced them with two G42s ... so I now have a G26.5 (arriving today, I hope), a G23.4 with a 9mm conversion barrel and the 42s.
The 42 will replace a Ruger LCPII for the few times I pocket carry, even though it's a bit bigger and prints somewhat. Mostly it gets carried IWB at 3:30 or abdomen and it's a joy to shoot due to the mild recoil and the speed with which I can make follow-up shots. What tipped the scales and why I bought another 42 at Blue Label pricing, was my 4th place finish in a BUG match where I was shooting with 36 other people. That's as good as I've ever placed in any recent pistol match and I credit the recoil for that.
Now, I understand the deficiencies of the .380 ACP, but the Lucky Gunner gel tests made me a believer in the 99-grain Federal HST hollow points for both penetration and consistent expansion through four layers of fabric. That was reassuring and I don't fret much about the power factor. However, in colder weather, I'll stick with the G23 or G26, both stoked with HSTs (124 standard pressure and 180-grain) simply because it's easier to conceal a larger gun with heavier clothing.
(As an aside, my LEO friends and a shooting buddy who is a forensic scientist all agree that shot placement is king in the world of gunfights, so being accurate with a .380 probably beats poorly placed shots in a larger caliber.)
I'm all done dabbling with other brands and, hopefully, other Glock models. As was pointed out, it's a major investment these days shooting enough ammo to verify reliability in ANY caliber, especially .380, so I plan to stick with the status quo for the foreseeable future.