Purchased the 24C for my M&P 15-22 in November 2017. Got a great deal at Primary Arms for 179.99 and around 7.00 shipping. The design of the Hiperfire (toggle springs) fascinated me to the point of "I have to try this". No regrets.
I feel the assembly as a whole when using the lightest pull weight toggle springs is very sensitive to external pressures such as holding the hammer, cocking it manually, etc. Goodness, those lightest "toggle" springs (gray color) really send the hammer home. Though I've seen other aftermarket triggers cause light strikes on rimfires, I don't anticipate any light strikes. I have several hundred rounds through the carbine with zero issues. Along with the 24C, I installed a set of the KNS 15-22 anti-roll pins.
I believe the lightest pull weight was advertised at 2.5lbs. Before installation I tested the factory 15-22 trigger which has been excellent. I used only my digital pull gauge and did 6 pulls. Average was 4lbs 6oz. Excellent compared to several I've read about. By far the sweetest "mil-spec" trigger I've experienced.
Did same with 24C. In a vise the 24C was ranging from just under 2lbs. to 3lbs.
During my live fire, I stopped at 15 rounds, put the rifle in my lead sled and averaged 1lb 6oz on 5 rounds. Brought out my old style gauge and it showed 1 1/2lbs to just a hair more than that. Definitely light but didn't feel dangerously so.
I noticed zero take up and you would have to know the trigger was resetting because I couldn't detect it. Perhaps if you were live firing for the sole purpose of determining reset you might feel / hear it.
Did not install the optional shoe though I can see where some shooters might like it on the flat trigger. I like flat triggers.
Assembly appears to be very well made. Customer support was quick to answer the phone and answer a question I had.
Based on my 14 month experiences I'd recommend the 24C.