how much of an improvement are the FMS springs?

[ChrisDrives121DA]

["and the fact that the kyb super specials seem to be discontinued,The bilsteins arent availible in the usa, (need to be imported big $$$)
Spax,AVO and ventura all make 33-40mm drop springs for the type DA 88-91 121 and kia pride, BUT again expensive to import."]






Spax germany told me that they donīt produce or stock these springs anymore. Neither here or in the UK.