There are two problems with poly LCA bushings.
1- they depend on the tolerances of the old LCA bushing shells, which are not exact
2- they get installed by people that think they can just slap them in there and they'll work (without bothering to check the fit of the bushing or the location of the LCA on the pin)
If the poly LCA bushings are installed properly, ie, the fit on the bushing shells is checked and the LCA is located properly by what usually has to be an adjustable strut rod, the poly bushings work fine. Greaseable pivot pins help too, as most were designed for use with poly bushings so they don't have an inner shell that is pressed onto the pin, so the outer diameter of the pin where the LCA bushing rides is constant. They also have a different style shoulder on the pin for retaining the bushing, and of course you can add grease if the poly bushing starts to squeak.
None of my cars squeak or clunk, and they all have poly LCA bushings at the moment. They also all have adjustable strut rods and greaseable pivot pins.