Just don't expect the Suplex suspension to make a huge difference. On reflection on my Roadster I wish I hadn't bothered.
Other opinions are also available
I think it depends on the starting point of the car and the kind of driving one does.
On my 1986 car with 140lb springs, the transformation was huge, I went from a front that was tooth-rattlingly hard, skittish, and totally unsuited to my driving preferences (twisty British B roads, which tend not to be surfaced that well) to a setup that was nicely compliant and gave a comfortable but controlled ride at my preferred driving speeds (50 to 70mph) on said B roads.
If I had a more modern car with better stock suspension, or if my driving was more on smooth 'A' roads or racetracks, then I guess the improvement would be a deal less apparent.
On Motorways, dual carriageways, and similar major roads of course, there's no measurable improvement. A stock car performs perfectly well on these surfaces and the Suplex system brings no benefit.
