Works pretty well on my car, but definitely not perfect. Mine seems fine up to about a 275 shot, past that distribution problems become very hard to tune.
I have a 7531 I use for ICM timing adjustments to try and even things out.
Overall I think this is a pretty good system. I've never used both stages on mine.
My car went from a 10.78 to a 9.14 on a 225 pill first time out this year.