The rubber ones are too soft when it comes to front to rear shift, they allow the LCA's to shift forward and rearward under braking and acceleration. The poly ones are great for that, the stiffer compound keeps the LCA from moving forward or back. But the poly bushings are also stiffer in the up/down travel, which isn't good. It adds resistance to the LCA when it's traveling up and down, and that keeps the suspension from moving freely.
Best bet for strut rods in my opinion is the adjustable ones that are available. You get to tailor the length to match your car's suspension so there's no binding, and they're basically solid when it comes to forward/rearward motion of the LCA. But the pivot freely up and down. Most of the poly strut rod bushings are also the wrong thickness, so if you use them with stock strut rods you're likely to have the strut rods be the wrong effective length, which will cause binding in the LCA.
