Well I did lots of suspension upgrades all at once so it would be hard for me to tell what each individual piece is doing. I'm running FF 1.06 bars, Hotchkis adjustable shocks, QA1 adjustable strut rods and a boxed LCA with the delrin bushing. From my understanding delrin provides a little more give than poly but less than rubber but is very smooth in it's rotation so it's very precise. I think since you already planned on stiffening the LCA and K frame as well as running Bilstein or Viking shocks, you won't really notice any comfort problems. Plus the delrin bushing gets rid of the outer shell that a rubber or poly bushing has so there's a little more material in there, don't know if it makes that big of difference.
My dart is "stiff" but not unbearable it's actually very nice and balanced to me because it's now a lot more predictable and it stays flat in corners which I really like. The better shock dampening and higher rate torsion bars, I think is the main key to everything.
