There are many trigger manufacturers out there. Timney is quite popular as is Rifle Basix, Triggertech, ELF, Jewell, Hart, etc..

I see that many trigger kits are half triggers and get mixed reviews. This seems highly related to what is left for the other 1/2 that is OEM.

Jard seems to make a trigger & sear kit for most makes. Who has tried these? What are you running and how does it work?

The only Jard I have installed in one of my rifles is the Ruger #1 trigger. Quality is top notch and I got a safe trigger pull weight that I never dreamed of getting with a factory (even 3 screw) trigger. On the Jard No.1 trigger the trigger and sear are one piece. RJ

I have installed Jard triggers for a few customers' AR rifles and they like them very well.. But that was before TriggerTech items were available.. FWIW.