I use vibrapods under my monitors. Great isolation. I was surprized as heck, but I also get terrific clarity. Deep bass gets a little boost (good thing for me), but with terrific solidity too. Others will disagree, but I've been running this way for a year and a half and love it.
Best Isolation for stand mount speakers
I am finding that careful use of isolation devices can bring my modest equipment to levels of performance far beyond what I expected, and though some of these devices are not cheap I, so far, find that the cost of sonic improvement is less than significant upgrades in major components. That being said I am pretty frugal and do not like throwing money around in search of the Holy Grail of musical bliss. I am looking at the possibility of some type of isolation cones, other, for my little Dynaudio's. They are currently on very solid, heavy stands. I've considered Herbie's pads, Ceraballs, Nordost, and perhaps Stillpoints but the cost makes me twinge a little for two sets. I would appreciate others experiences and inputs. Thanks.