SME IV and FDIV trough kit - improvement?

[Dogberry]

I'm considering adding damping troughs to a pair of Series IV arms, resolving one of the differences between them and the Series V. I suppose if it turns out to be a success I could do the same to the 309/M10 arms as well.
Has anyone any experience with the effect of adding a trough on the IV? I have used the V with damping and without, and I like it best with the paddle just dipping into the silicone.

Chris

 

[Dogberry]

Perhaps I now know why few have tried as an experiment: they cost £369.02 (ie $466.72USD) each!