Isolation for power line conditioner?

I have heard that many gain good results by providing isolation for their PLC units and was wondering what type of suggestions/experience folks out there may offer. I do currently have my line conditioner (Sound Application XE12-S) on a slab of MDF on aluminum cones. I put this together awhile back for the PLC I had at the time, and chose this route simply cuz I had the stuff lying around and it seemed to be better than nothing. That aside, considering this particular unit is, I believe, primarily a passive component, what solutions and ideas can you throw my way? Thanks in advance!
Jim Weil, the designer of Sound Application, has worked extensively over the years to try to limit the effects of mechanical resonances on his passive line conditioners and he is never fully satisfied with their immunity. This is a testimony to the fact that passive plc's sitting on the floor are subject to micro-shaking, resulting ultimately in some smearing of the audio signal. Whether isolation devices help more than they hurt is another question; I've never found external treatments to be overly helpful.
A related comment - I've often found the passive network boxes on networked cables to be quite vibration sensitive. Setting them directly on the shelf of a rack has resulted in very audible smearing, which is eliminated by hanging them or attaching them to the wall.
This is a subject I would really like to understand - and don't.

I continue to disagree with Stehno. Floorborne vibration is a far bigger problem, especially on raised hardwood floors, than airborne. The surface area of a network box for airborne interactions is small.
It does make a significant difference. Those airborne resonances have the same deleterious effect as those microphonous meanies in amplification and the like. go figure. 'tis why I go for coupling. Attainable. And all resonances go to mother earth. Even from ICs, power cords, and particularly, my Sonoran speaker cables. peace,warren
Not withstanding Jim Weil's efforts, the Line Stage in my system is improved substantially by being on a level 2 Mana stand.

I should also note that many of the better ac power cord efforts focus on resonances, the Harmonix comes to mind.
But also note that some of the best, clearest, most resolving, and least smearing power cords do not have mechanical resonance treatment. This subject is still controversial.
It's my experience that you should play with vibration control at any place you think it matters and also where you don't think it will.....
I have vibration treatment in the power conditioner and the MIT network boxes. Have elevation / vibration in my speaker cables and have found interesting changes in the sound that I like. This is system dependant as I have tried in some friends some of the tweaks that have worked for me with less success. Flex good point on the controversy.
My mains two blade switch uses plate type fuses so all current getting in the house passes through this thin metal sheet (vibration prone right!) so I changed them for elastomeric tweaked ones and I liked the change Just to give you an example of thinking out of the box.
Even your TV set if you apply some vibration tweak to it you'll find nice changes in picture quality
Happy tweaking