Let me just say that I have taken out the pigtail spring, polished smooth all of the contact points on the sear and trigger arm, and the contacts of the sear and the striker.

IT FEELS TONS SMOOTHER, maybe the smooooth feeling, feels "lighter" and it does feel lighter, but it may just be the smoothness, making it feel lighter..
My gun had a terrible "gritty" trigger pull witht the slide off, stock....its very smooth now...

I had one "failure to reset trigger" but this was before I did anything....since my trigger work I have had NO problems whatsoever....

SO even if it doesnt actually Lighten the trigger, a good polish job DEFINATELY smooths everything out, and very worth it IMO!!