||I also did ES subframe bushings at the same time as well as Tokico Illumina adjustable shocks and Tanabe springs. New ball joints, tie rods, FUCA, RUCA, tension rods and then Z1 upgraded lower control arms...
I can't say exactly how that changed the feel of the differential because I did so many other things at the same time but I'm very happy with the results. For the price difference to Nismo bushings ($30 vs $300) I would do it again.
I'm not sure if I would ever do solid bushings unless I was going full race car.