I decided to put my Gen II 19lbs. injectors in today and they all worked just fine. I had a connector issue with injector one but that's just due to a bad contact on the connector itself, some electrical contact clean and a little wire jiggling later and I had it running just fine.
It seems to accelerate smoother, but this could be due to the fact that these injectors were rebuilt and not just some junkyard injectors. Thus, making them an improvement over my 140k mile stock ones.
I will say for a fact that I can accelerate past 3k RPM better than before. That needle increases steadily until it hits 3k and then it takes off to 4k RPM before slowly increasing again. (Of course I rarely take it past 4k RPM). The only other mods I have done are the 4.0TB and Taurus fan mods. (In contrast, these mods seemed to help my Low-End power)
So over all, it gave me a smoother and quicker acceleration as well as some more Hi-End boost in the 3-4k range. No difference down low though. (That I could feel anyway)