I've finished an upgrade on my car to swap out most of steel heim joints for Spohn Performance Del-Sphere Pivot Joints. It uses a mono-ball with Delrin liners. It really lowers the NVH associated with steel heim joints, without giving up the accuracy. Plus they are rebuildable and greasable. Good stuff.
Thanks guys. I wanted to share that these parts exist... one doesn't have to choose between the accuracy and lack of bind of a steel rod end vs the lack of NVH of a poly or rubber end.