[TSAX]

Speaking from my Gen4 19 experience...

I replaced the trigger/trigger bar assembly with a Glock gen3 17 smooth face trigger SP00357 (from Glock Parts). It was like $18 or so.

This improved my trigger pull a bit without doing anything else.

Then, I read/watched videos on the 25 cent trigger job. I didn't use a Dremel, but rather a Q-tip and some Mothers Mag & Aluminum polish to lightly rub the surfaces about a dozen times, then wiped off. The polishing did smooth out the surfaces a little bit.

I then applied a very, very light coat of Tetra gun grease on the polished surfaces and rubbed "dry" per Tetra's instructions (the grease is still there).

The result was a very nice, crisp and smooth trigger pull.

As much as I like the Gen 4 guns, its too bad Glock didn't just find away to do what you just did stock or at least have the Gen 3 G26 trigger bar with the serrations.