Jeez The money is high! You require the New Black Topyoke for fitment.(This also allows repositioning of bars 1cm further away.)
Guess you may be able to drill and tap original topyoke
As for usefulness. Have to say that it certainly builds a confidence in you Occasional large Bumps in road surface do not cause bars to waggle as quickly. Just an initial bump and then all is fine.
Have had mine fitted for almost a year now(although not that much mileage ) Infinate adjustment. Mines is set quite light.
As for worth the money >£500 over here. Well it's that Old cliche "What price is a Life" ?
I personally have experienced a terminal "Tankslapper" on the road at over 100mph on an FZR 600. I was extremely lucky.(Catseye, Straight road. No furniture)
Any Sports bike I have bought since(1990) has had a Steering damper.
Cheers
Steve