I will say it's a little 'firmer' of a ride.. It did lift the rear end by about 1/2" from stock. But, for me, that's what I was looking for.. :)
I did put a bit of tension on them when unloaded, thus the 1/2" lift.. But, driving over the local speed bumps we have in our neighborhood, it was not any more 'stiff' than before, but it is 'firmer' overall.. I know that probably does not make much sense, but until I get some real miles under my belt with them, I can't say right now how much it helps or or deters from the original ride.
But, I did have them on my old 97 F150 forever and I really liked them on that rig..
Mitch