Definitely gives it a better ride doesn't it Hans. Neither too hard, nor too soft. I converted both my cars Convertible and Coupe. Never looked back.
Dead easy to do if you have a spare subframe and an arc welder.
Geoff Watson can supply the kit as a set of parts. They were originally devised as part of the set up for the K series and then later the V-Tech Honda conversions that they did for the Minis.
http://www.watsonsrally.co.uk/I worked out that they'd fit on an A series too as the hydrogas units are more or less dimensionally the same. The upper arms sit slightly different but that doesn't affect the fitting of the springs much.
Saves having to modify the body and put extra pressure on the fibreglass which you would do with coilovers unless you captured the head of the coilover on the subframe like the TF MGF subframes do.
There was only one rate for the springs when I got mine. Not sure if I heard it right that they do now do a road and race set.
Rich has them on his car too.
