I thought I'd follow up on this. Not the fairest of judgements - as I replaced the front top mounts at the same time, but the rear is a little tighter in the bends and all round, the car is much more stable, nice and grippy again without a hint of understeer. Its very even and composed in the bends, but you can certainly feel the tyre on the road, quite literally, the tread and texture of the road.
The poly bushes were easy to fit, anyone that moans about removing rear beam bushes is a girl (fitting OEM units is probably another story).
