I have used morone formulas on 2 of my past cars and my dad had used them on several other cars. They work real well and last for many years. I got a set of tokicos and springs and arms that I havent put on the car yet still sitting in the garage. The car still has its drag set up on it.
I have the Steeda Sport springs and the Tokico illumina 5 way adj shocks. Freakin expensive shocks. But I wouldn't trade them for anything. I think the ride quality is what I would call tight. Not smooth, not rough. My perception though. The Sport springs lowered the car about one and a quarter inches. I have the Steeda subs welded in and the Steeda rear uppers and lowers. Front G-track and strut tower brace. Check my sig. I also replaced the stock seats with the Corbeau seats. I love the ride. I love the handling. Just need new tires...
Hope that helps.
I had a rough ride too, and changed all the shocks out in the back with the Tokico blue shocks. Non adjustable, but damn it smoothed out the ride. It is still rough over bumps and what not, and I think it's inherent in mustangs. The rough ride in my car was due to a stuck shock...it would compress ok, but not return.