Hmm..had you had your Patriot there and drawn them back to back SA you might have noticed a bigger difference using one's fingers.
My 70 lb 2002 Pat SC feels like a mack truck compared to the Liberty regardless of what I'm pulling it back with. That 2002 I-cam really hits peak late. They've solved that problem though on the 2004 I-cam. Much nicer back end on the draw cycle.
Like I said..if you don't want a Liberty, don't shoot one, cause if you do shoot it, it's hook, line and sinker...