They work well Tom, all the "Post Clasic Racers" here in Oz use them to tame "Tank Slappers" at speed, and while a taper roller bearing kit and new bronze swingarm bushes will go a long way to curing those drama's, the damper is the icing on the cake, so to speak.
I was extremely lucky to pick up a "Whitepower" damper (not made in Alabama, surprisingly........) for a song on Ebay because the seller didn't know what he was selling, and I forgot to tell him, ha ha! The damper was for a modern sports bike, so i'll have to fab up some alloy brackets, but no biggie, they're very simple to fit, and having had one on my BMW R100RS for 12 years, I can attest to their usefullness. Cheers, Terry.