Slight threadjack :
Were the OE self levelling shocks on the estate any good when new? Mine are buggered and don't want to go to the (relatively speaking) vast expense of replacing them only to find it still wallows around like a yacht in a storm
And no, I don't ever drag a caravan or transport more than two dead bodies at once.... or have any need for an estate really.
It's an Elite. With Elite suspension. Wallow is what they do, then they wear the tyres and refuse to go straight as well. But they are comfortable, very good motorway mile muncher, but you simply can't rush it in the twisties or get on the power until the suspension sorts its knickers out.
If you crack on a bit, and live in an area with even half decent roads, then bin the lot and fit lowered sport chassis mv6. But re sl shocks, specifically, they will work with any suspension set up, so if fitted in conjunction with lsc mv6 for example, and you then replace the sl shocks for conventional (b4) shocks, you will notice a big improvement in the independence of the rear suspension, less "porpoising" or body roll.
However, you can't just fit standards type non sl shocks to sl springs, as the springs are so soft as said. The suspension needs replacing as a set. Shocks and springs all round on an Elite.