Jon, just looked at their web site. It would be nice to think that you dont end up were you started with them already being a supplier of some of the crappy ones. Mind you, saying that if you put some untrained guy in the supply chain who picks something that he thinks is right...... then you have fun.
I used to select antivibration mounts for diesel generators. I spent time finding the centre of gravity, weight per point and isolation required which dictated how much they sunk. Nice little exercise especially if the set was in a hospital under a revovery room. In my absence and with some management changes people would pick them from a photo in a catalogue.
Not good seeing a v16 wanting to walk or dance.
So maybe there had been some incorrect specification going on. Fingers crossed. As J Clegg once said to me, we have thrown better old ones away fitting crappy new ones. Over the last 20 years i have had no luck with rubber bushes. My opinion of decent poly is that with care and corect washers there is no problem with front bones. Rear outer are worst due to space and landing surface. Rear inner can be destroyed by inaccuracy of A frames and also chassis mounts due to same reason. I know in the past we have done this to death but point side loading will chew up the inner rears if the spacing is wrong.
In an old post of mine i spent hours bespoke fitting new A frames to a new chassis to equalise loading. Scale drawing and hours of filing. Ceejay followed up with his great advice. In the fullnes of time i will be doing what he says.
Whilst rubber bushes are forgiving when shoving in the rear A frame to the chassis they will still be under stress if there are inaccuracy in the components. Just pointing this out having been astounded when offering A frames up to a chassis without bushes to see clearance.
My two pennies worth having run, rubber, 3 types of poly and also rose joints.
Mike