I carry a G19 loaded with the Speer 124 gr +p Gold Dot.

It supposedly tests well and it's extremely popular. However it's bare gelatin performance is just at 12 inches. (the bare minimum recommended by the FBI)

Anyway I have that because I'm out of good 147 gr JHP's. 147 gr ammo doesn't "feel" like it's stressing anything. The gun just "rolls" a little more and the muzzle "flips" a little less. Muzzle blast is reduced and there is no sonic crack down range. Overall it's more pleasant to fire.

That being said 1300 fps 115 gr +p+ ammo (To include the gold dots) does feel "harsh" and recoil is stronger than you'd expect from your 9mm. I've never fired any hot 147 gr ammo but I'll bet it starts to recoil closer to a bigger caliber at that point.

I've only used Underwood Ammo in a glock 20 10mm and it was great ammo. Very accurate. However I did get two failures to feed in 100 rounds and I suspect the hot ammo (factory recoil spring) was the culprit.

I would not trust my life to ammo that runs a gun on the ragged edge of safety or reliability.

Moving up in caliber is the more reliable move if you want faster / bigger bullets.