I cannot say that I am totally surprised by your findings. They are similar to what I have seen locally. I would offer that the slightly stiffer draw cycle and shorter valley on the Outback is the reason for speed advantage it has over the Liberty. The Outback's mass weight is what is taking the recoil and vibration out of the bow "better" than the Liberty.

Out of curiousity, were both 70 pound bows set to 60 lbs?

Thanks for the info.