I also was planing to get the Langdon trigger kit, but I noticed that the stock DA trigger is good enough for first draw shot. I do AIWB carry, when I practice drawing and have my finger on the trigger at 45 degrees moving into 90 degrees as I point it in front , with a lighter trigger pull than stock, there’s a tendency that your trigger finger put more pressure on the trigger face since your forearm muscle is shortening as you move your arm up. (Forearm muscles control your fingers, btw)I got and already installed the Langdon kit with the 12 lbs spring.
DA went from 12 lbs to 9 lbs.
SA didn’t change, 4.5 lbs.
I tested it with IMI NATO ammo (9mm)and it was 100% reliable.
Yes, I do recommend the Langdon kit.
If you do appendix carry, try a quick draw as you move your arm up with trigger already slighty being pulled back, you’ll notice, it doesn't need much effort to pull the trigger from DA position on a stock setup.
This actually changed my mind to keep it stock.
The SA trigger is awesome by the way!