No great loss: they aren't very good compared to what's available now since they had limited extension adjustment and no compression adjustment (and were extremely soft on compression, which is why they recommended not using them on big-block cars).

I had a set for B/E bodies where one stopped working. Koni said they could still rebuild them, but the cost was at least twice what I paid for the set originally. I got tired of them taking up shelf space about a year ago and sent 'em to the scrap heap.

BTW, any good hydraulic valving design is "speed sensitive". A progressive shim stack allows for light damping at slow shaft speeds and increased damping at faster speeds. This goes back to the fact that "traditional" car dampers are freakin' archaic compared to what any production motocrosser made in the last 30 years came with.