Everyone on my car forum has been raving about these poly bushings. I now see why.
My car had broken rubber bushings from 100k miles of great salted winters in the north USA. I had the old bushings pressed out at a shop and put these in BY HAND.
Quite a performance increase over stock, and my alignment was much better too, as the camber is non adjustable, but parts are where they are supposed to be! You will still likely need an alignment after replacing suspension bits.
Car holds better in turns now and has a bit more road noise over bumps. I'd call it firm but compliant. Better then stock.