Thankyou for your input guys, Walter kind of answered my question. I'm not interested in high/low speed compression adjusters, I figure if the shocks are set-up with the right valving to suit spring & rider then there is not a great need to be adjusting anything.
If the shock is under the control of the light spring (as in dual-rate springs) for, say, for 70mm of the first part of the shock travel, then I want the damping to be light enough to let the suspension work correctly. When the shock is under the control of the stiffer spring for the next 70mm I want the damping to be strong enough to control the spring.
I'm not interested, for now, about speed related valving changes, just 'piston position' related valving. Walter I don't think one should have to buy a YSS with hi/low comp adjusters just to get a shock that matches dual-rate or progressive springs.