I'm using Unique in them. And today I tried them from 5.0 up to the max and it didn't seem to matter about where they hit. Still 2-1/2" low. That wouldn't be a problem if I were to shoot them a lot, I could just adjust to that.
But I think they shoot the most comfortable at 5.3 or 5.5 and don't shove back as much.
I'm pretty happy with them, but they are kinda wasted on my cardboard targets. I'm going to find something fun to shoot when I take them out again. Maybe some boards or various items the locals leave at the county dumpster (1/4 mi. from me)
[It's a great source of target material. I'm always bringing something home and taking it back in a highly perforated condition.]