It would seem that, as with most things, we just need to try the dampers out in our own systems to see if they make a positive difference. The Herbies do seem to be the way to go as the price is minimal and most of the posters in this thread have had a good experience with them.
Let us know what you decide to do, Vlad1456.
Holly
Let us know what you decide to do, Vlad1456.
Holly