Poly RTABS or Rubber OEM RTABS Lemforder
I had powerflex in my vert and I didn't notice the ride changing at all. My RTAB's weren't shot to begin with and the only difference I felt was more grip in the rear end. It sorta felt like I added more weight to keep the rear end stable. For $80 and a $80 install I was very satisfied.
-2005 SMG ZCP Coupe
-1967 Mini Cooper