I was pretty hard on Pro Systems a while back, but after tuning with an O2 recorder, they (2-750ish's tunnel ram) weren't that far off as far as fuel curve and jetting.

Where i was really irritated was the idle and off idle initial performance.
Moving the idle jet to the lower position and some minor tweaking got them working quite well. I'm working with a pair of Dambest's now, so we'll see how they compare this season.

My brother bought a 906hp Hemi from Barton a while back and it came with a Pro Systems 1250 on it.