Others may beg to differ but in regards to panhard bushes I find super pro poly outlast stock rubber 3-1. This is on the defender and majority is gravel corrugates and bush work. Havent really used the Disco enough to make a judgement call . The thing I find with poly is 1, you can see when they are worn, rubber as I said can go soft and still look ok; 2 easy to replace no press,hacksaws,hammers,chisels,profanity,oxy/acet required
Cheers Scott