Beans said..
I have a 84 SSS with a lift adapter that isn't that good as it doesn't have the wedge fitting and relies on the 2 -6mm bolts holding it and I should switch to Axis . It's very stiff but very heavy . Would I buy another one
YES
If for some reason the adaptor is loose you could just recast the mast foot to make it a perfect fit again and then it will be super tight and perfect and won't rely on the screws a much.
Recasting the foot is super easy. I have a full step by step write up on this if anyone ever wants to try.
Weight on the masts is 1.9-2kg for the SSS and 2-2.1kg for the SS Approx. Masts are pretty much solid carbon cured in Autoclave so quite hard to make super light without taking away some strength. Always something to work on though for the future.