Not sure why it matters what I have....but anyway.
EG4, Ohlins DFV 14/6.

Currently running 14kg/mm springs in the front, you can sometimes get quiet a harsh ride when matched with bad shocks. The Ohlins aren't too bad but you sometimes get that "crash" when hitting big bumps at speed.
The collar kit softens this soooo much! Basically taking the edge off a harsh ride. Springs definitely don't feel like 14kg items anymore. Makes the car feel that little bit more refined, almost to DC2R standards.
Basically is doesn't feel like your fillings are going to rattle out.
Add to that, bumps are more controlled. You don't spear or dart off, the car moves in one motion. Such an old car can feel disjointed at times when driving over bad surface or chassis flex under load.