My friend bought a set of red ones for his 156, he has mounted them in January (front and rear). So far no squeaks or knocks, only thing you should be aware is to apply enough grease. Use white grease. As much as you can.
After a good feedback from him I also ordered a set for my 147. Also red ones. I will mount them in few weeks and I will let you know how do they perform.
My car is still on original bushes and with almost 200.000km on the clock. Quite good I would say