As author of the 15 Minute Practical Trigger Job I appreciate the kind comments.
FrankSquid is correct... the sear surfaces are hardened, and removing material will likely go through that SURFACE hardening. That is why I recommended only the fine polishing with the compound. Really what we are doing here is just removing anything really gross, and lightly lapping the hammer to the trigger.
The second important thing is, no angles were changed. Yes, the main improvment comes from the lighter springs. The stock M16 springs are way much stiffer than needed. With the semi auto AR15, we are more concerned with accurate fire, good trigger control. We are not so concerned with extreme conditions, vibration from full auto fire, etc.
Most importantly, the method is simple, and reversable. I have had NO reports of any problems other than a few FTF with some types of surplus ammo. With ammo of any quality, no problems. And if you insist on firing this ammo, you can drop in new springs (cost $3).
Full sear engagement is maintained, no safety compromises. No angles are ground. We don't want shooter100's problem.
The method is repeatable, and easily doable by others, with the same results.
If it were not for all of these factors, I would not have printed this up for all to try.
I ask you all this... if you try this method, do no other modifications. If you do additional modifications, please do not claim to have done the "15 Minute Practical AR-15 Trigger Job".