I just polished the internals and added the MCARBO spring kit to my M&P 40 1.0 full size. The pull went from over 6 to around 4lbs with zero creep. I am impressed to say the least. I highly recommend this kit.
I did the same with my Shield 1.0 .40 - WOW! Wife didn’t want me doing hers until I did mine, then she immediately said “orders one and do mine…”