I have been carrying various Glocks at my PD job for 25 years. My off duty gun for quite a few of those was my Glock 26.

When the Shield first came out, a friend bought one and let me borrow it for a couple weeks to shoot and check out. I loved it so much that I bought the first one I could find (this was when Shields were almost impossible to find, it took me about 3 weeks to find a store with one in stock). It has been my off duty carry since I bought it and qualified with it.

For me, the Shield is a superb option for CCW. On mine, and most I have tried, the trigger is very Glock like. Light take up, a well defined wall, a reasonably crisp break, then an audible and tactile reset. No mushy trigger with no discernible reset like earlier M&Ps. The trigger is a little heavier than my Glocks, but not by much and the trigger is crisper than the Glocks, which make it seem somewhat lighter than it really is. Mine has been 100% reliable through a couple thousand rounds, even reliably feeding and shooting some of my older reloads that didn't feed well in my Glocks. It is also very accurate for what it is. Last year at qualifications, we had some time while waiting for dark to do the night shoot, so one of the guys wanted to do a competition. We were sitting in lawn chairs at about the 100' line. He proposed that we each draw and shoot 1 round while seated, taking as much time as we wanted to aim, but only shoot 1 rd. The person who got closest to the absolute center of mass won. They all used their full sized duty guns, I used my Shield. I won by a long shot. My shot was perfectly centered and, if we had been using B27 targets, it would have cut the exact center of the X ring. I'll freely admit there was a lot of luck involved, but the Shield was easily up to the challenge. Mine is a 1.0, from what I have read and seen, the 2.0 isn't much different except for the more aggressive texturing.

I had an opportunity a couple years ago to shoot a Glock 43 owned by another Officer. I absolutely HATED it. The gun itself was fine, the issue I had was that the gun didn't fit my hand well. When firing, the butt slammed into the joint in the base of my thumb. It slammed me so hard that my hand was sore for 2 days after firing 2 mags. Again, not a slam on the gun, just the way it fit my hand and I have never heard anyone else with this complaint. It was nothing at all like my G42 and I was sorely disappointed. The G43 was more snappy than my Shield, but not bad. I will say that the G43 I shot was eerily accurate, even more so than my Shield or almost any gun I have ever shot. After 1 mag at 7 yds, I went back to 50 ft for the second mag and my group was about the same size as it was at 7 yds, almost 1 ragged hole. The trigger, with the new trigger setup on the G42, G43 and Gen5 guns, was very good. A little heavier than the older Glocks, but VERY crisp for a poly framed gun. Reset was even more audible and tactile than older Glocks. For me, the G43 wouldn't fit in my pockets and I already had my Shield for IWB. It didn't do anything new and exciting for me, and it hurt me to shoot it, so I never bought one. If it had been small enough for me to pocket carry, I would have sucked up the pain and bought one to replace my G42, but it didn't, so I didn't.

Bottom line, either the Shield or the G43 would work well for IWB. The Shield is a little bigger, a little more capacity and easier to shoot. The G43 is smaller, lighter and easier to conceal. The best thing you can do is shoot each, decide which you like better and go buy one.