This is a very interesting thread, and thank you Robbie for your very impressive and tangible description of the effects of PR. Your report may lead to me having a PR installed on my 2014 4/4.
So far I was hesitant and ambivalent due to different experiences with PR. On the 2010 Roadster the retrofitted PR was very uncomfortable. Probably it was the wrong geometry when it was installed by the workshop? or simply the wrong PR? Either way, every bump was translated into a very disturbing strong lateral movement. After a week I had the PR removed again.
It was completely different with the Plus4 SuperSport. The PR was newly installed ex works. The car drove very well and controlled, without annoying lateral movement.
I think Simon is right there. It must be exactly the right PR. If possible, one that other drivers in the same 4/4 type with BTR axle, since about 2011, have already had positive experiences with.
One more question on this. Despite the 4-seater 4 leaf springs, the spring will coil in first gear if the throttle is too high. Does this damage the PR and do I need additional anti tramp bears?