I still have a 43X and a 43 frame. Depending on the occasion and need, I can configure it how I need. I also have been running the Z9 mags in my 43, which has negated the use of the larger 43X frame in most cases. I haven't ventured into the Shield S15 mags, again, I would just carry my 19.
Yes, the 43 is snappy, but I also don't notice much of a difference between it and the 365 I had. My 365 was 100% reliable as well as my 43X and 43, even with the Z9 mags. I guess I'm lucky, as I also have a 42 that has well over 5k rounds through it without a single failure.
IMO if I was going to carry a 26, which I did for a bit years ago, I'm just going to carry my 19.
I could what if all day, but in the events I have been directly involved with, 15, to 30 rounds was all that was required. I easily have that many on my person at any given time with any of my current off duty rotations. YMMV
TXPO